Detecting apparatus and display apparatus

ABSTRACT

According to an aspect, a detecting apparatus includes: a touch detection electrode provided along a touch detection surface; a strain gauge integrated with the touch detection electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Application No.2016-066717, filed on Mar. 29, 2016, the contents of which areincorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present invention relates to a detecting apparatus and a displayapparatus.

2. Description of the Related Art

Display apparatuses have been required to detect a touch operationperformed on a display surface and detect pressing force or forceapplied to the display surface by the touch operation. There have beendeveloped simple techniques for satisfying the requirement, including atechnique described in Japanese Patent Application Laid-open PublicationNo. 2013-186501 (JP-A-2013-186501), for example. The technique describedin JP-A-2013-186501 includes both a touch sensor that detects a touchoperation performed on a display surface of a display apparatus and aforce sensor that detects force applied to the display surface.

SUMMARY

According to an aspect, a detecting apparatus includes: a touchdetection electrode provided along a touch detection surface; a straingauge integrated with the touch detection electrode.

According to another aspect, a display apparatus in which a plurality ofpixels are arranged in a matrix includes: a drive electrode used todrive the pixels; and a strain gauge integrated with the driveelectrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary configuration of a displayapparatus with a touch detection function according to a firstembodiment;

FIG. 2 is a diagram for explaining the basic principle of a capacitivetouch detection system and illustrates a state where a finger is neitherin contact with nor in proximity to a touch detection electrode;

FIG. 3 is a diagram for explaining an example of an equivalent circuitin the state where a finger is neither in contact with nor in proximityto the touch detection electrode as illustrated in FIG. 2;

FIG. 4 is a diagram of an example of waveforms of a drive signal and atouch detection signal;

FIG. 5 is a diagram of an example of a module provided with the displayapparatus with a touch detection function;

FIG. 6 is a sectional view of a schematic structure of a display devicewith a touch detection function according to the first embodiment;

FIG. 7 is a circuit diagram of arrangement of pixels in the displaydevice with a touch detection function according to the firstembodiment;

FIG. 8 is a perspective view of an exemplary configuration of driveelectrodes and touch detection electrodes in the display device with atouch detection function according to the first embodiment;

FIG. 9 is a schematic wiring diagram of exemplary arrangement of forcedetectors provided in the display apparatus with a touch detectionfunction;

FIG. 10 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 11 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 12 is a block diagram of an example of a functional configurationof a circuit that detects force;

FIG. 13 is a timing chart schematically illustrating the relationbetween a display drive timing, a touch detection timing, and a forcedetection timing in the display apparatus with a touch detectionfunction;

FIG. 14 is a block diagram of another example of the functionalconfiguration of the circuit that detects force;

FIG. 15 is a timing chart schematically illustrating the relationbetween the display drive timing, the touch detection timing, and theforce detection timing in a case where touch detection and forcedetection are performed in parallel in the same period;

FIG. 16 is a block diagram of an example of a functional configurationof the circuit that detects force in a case where touch detection andforce detection are performed in parallel in the same period;

FIG. 17 is a diagram of an example of the relation between a voltagewaveform of a pulse that is output from a voltage application circuit,an output from an amplifier, and an output from a comparator in relationto the output from the amplifier;

FIG. 18 is a diagram of an example of a configuration of the forcedetector and a portion near the force detector according to a secondembodiment;

FIG. 19 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector according to thesecond embodiment;

FIG. 20 is a diagram schematically illustrating an exemplaryconfiguration that selectively operates two systems;

FIG. 21 is a diagram schematically illustrating the relation betweendrive timings of the two systems, coordinate calculation based on theresults of touch detection performed by the two systems, and forcecalculation based on the results of touch detection performed by the twosystems;

FIG. 22 is a diagram schematically illustrating an example of differencebetween an output from a second system and an output from a first systemobtained when no force is applied;

FIG. 23 is a diagram schematically illustrating an example of differencebetween an output from the second system and an output from the firstsystem obtained when force is applied;

FIG. 24 is a diagram schematically illustrating another example ofdifference between an output from the second system and an output fromthe first system obtained when force is applied;

FIG. 25 is a diagram schematically illustrating an exemplaryconfiguration that operates the two systems in parallel;

FIG. 26 is a diagram schematically illustrating an example of outputsfrom the two systems obtained when no force is applied according to afirst modification;

FIG. 27 is a diagram schematically illustrating an example of differencebetween outputs from the two systems obtained when force is appliedaccording to the first modification;

FIG. 28 is a schematic wiring diagram of exemplary arrangement of theforce detectors according to a third embodiment;

FIG. 29 is a diagram of an example of a configuration of the forcedetector and a portion near the force detector according to the thirdembodiment;

FIG. 30 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector according to thethird embodiment;

FIG. 31 is a schematic wiring diagram of the relation between the forcedetectors and the touch detection electrodes according to a fourthembodiment;

FIG. 32 is a diagram of an example of a configuration of the forcedetector and a portion near the force detector according to the fourthembodiment;

FIG. 33 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector according to thefourth embodiment;

FIG. 34 is a diagram schematically illustrating an exemplaryconfiguration that selectively operates the two systems according to thefourth embodiment;

FIG. 35 is another diagram schematically illustrating the exemplaryconfiguration that selectively operates the two systems according to thefourth embodiment;

FIG. 36 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector according to asecond modification;

FIG. 37 is a diagram of an example of a module provided with the displayapparatus with a touch detection function according to a fifthembodiment;

FIG. 38 is a diagram for explaining a basic principle of self-capacitivetouch detection and illustrates a state where a finger is neither incontact with nor in proximity to a touch detection electrode;

FIG. 39 is a diagram for explaining the basic principle ofself-capacitive touch detection and illustrates a state where a fingeris in contact with or in proximity to the touch detection electrode;

FIG. 40 is a diagram of an example of waveforms of a drive signal and atouch detection signal;

FIG. 41 is a diagram of exemplary arrangement of the touch detectionelectrodes;

FIG. 42 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector according to thefifth embodiment;

FIG. 43 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector according to thefifth embodiment;

FIG. 44 is a schematic wiring diagram of exemplary arrangement of theforce detectors according to a sixth embodiment;

FIG. 45 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 46 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 47 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 48 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 49 is a timing chart schematically illustrating an example of therelation between touch detection timings and force detection timingsaccording to the sixth embodiment;

FIG. 50 is a schematic waveform diagram of an example of the relationbetween a synthesized signal for forming capacitance between the touchdetection electrode and the drive electrode, a drive signal for touchdetection, and a drive signal for force detection;

FIG. 51 is a schematic wiring diagram of exemplary arrangement of theforce detectors according to a third modification;

FIG. 52 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 53 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 54 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 55 is a diagram of an example of a specific configuration of theforce detector and a portion near the force detector;

FIG. 56 is a timing chart schematically illustrating an example of therelation between drive timings of the drive electrodes and touchdetection timings of the touch detection electrodes in touch detectionaccording to a fourth modification; and

FIG. 57 is a diagram of an example of a sectional structure of anorganic EL display device.

DETAILED DESCRIPTION

Exemplary embodiments according to the present invention are describedbelow with reference to the accompanying drawings. The disclosure isgiven by way of example only, and appropriate changes made withoutdeparting from the spirit of the invention and easily conceivable bythose skilled in the art naturally fall within the scope of theinvention. To simplify the explanation, the drawings may possiblyillustrate the width, the thickness, the shape, and other elements ofeach unit more schematically than the actual aspect. These elements,however, are given by way of example only and are not intended to limitinterpretation of the invention. In the specification and the figures,components similar to those previously described with reference topreceding figures are denoted by the same reference numerals, anddetailed explanation thereof may be appropriately omitted.

In this disclosure, when an element is described as being “on” anotherelement, the element can be directly on the other element, or there canbe one or more elements between the element and the other element.

A conventional touch sensor and force sensor require a space for parts,wiring, and other components for their configurations, thereby placingrestrictions on arrangement of parts, wiring, and other components forother configurations. If both the conventional touch sensor and theconventional force sensor are simply provided in one apparatus, theapparatus is more difficult to design. Even if the apparatus can bedesigned, the cost increases because of dedicated components provided intheir respective configurations, for example.

For the foregoing reasons, there is a need for a detecting apparatus anda display apparatus that can detect force with a configurationintegrated with a component used for another configuration.

First Embodiment

FIG. 1 is a block diagram of an exemplary configuration of a displayapparatus with a touch detection function according to a firstembodiment of the present invention. A display apparatus with a touchdetection function 1 includes a display device with a touch detectionfunction 10, a controller 11, a gate driver 12, a source driver 13, adrive electrode driver 14, a constant voltage circuit 15, and a touchdetector 40. The display apparatus with a touch detection function 1 isa display device in which the display device with a touch detectionfunction 10 includes a touch detection function. The display device witha touch detection function 10 is a device in which a liquid crystaldisplay device 20 is integrated with a capacitive touch detecting device30. The liquid crystal display device 20 is a liquid crystal displaydevice including liquid crystal display elements serving as displayelements. The display device with a touch detection function 10 may be adevice in which the capacitive touch detecting device 30 is mounted onthe liquid crystal display device 20 including liquid crystal displayelements serving as display elements. The liquid crystal display device20 may be an organic electroluminescence (EL) display device, forexample.

The liquid crystal display device 20 sequentially performs scanningbased on a scanning signal Vscan supplied from the gate driver 12,thereby performing display. The controller 11 is a circuit that suppliescontrol signals to the gate driver 12, the source driver 13, the driveelectrode driver 14, and the touch detector 40 based on video signalsVdisp supplied from the outside, thereby performing control such thatthe gate driver 12, the source driver 13, the drive electrode driver 14,and the touch detector 40 operate synchronously with one another.

The gate driver 12 has a function to supply the scanning signal Vscan toscanning lines GCL coupled to sub-pixels SPix serving as a target ofdisplay drive in the display device with a touch detection function 10based on the control signal supplied from the controller 11.

The source driver 13 is a circuit that supplies pixel signals Vpix tothe sub-pixels SPix, which will be described later, of the displaydevice with a touch detection function 10 based on the control signalsupplied from the controller 11.

The drive electrode driver 14 is a circuit that supplies a drive signalVcom to drive electrodes COML, which will be described later, of thedisplay device with a touch detection function 10 based on the controlsignal supplied from the controller 11.

The constant voltage circuit 15 is a circuit that supplies constantvoltage Vt to force detectors 71 and 72, which will be described later,of the display device with a touch detection function 10 based on thecontrol signal supplied from the controller 11.

The touch detector 40 is a circuit that determines whether a touchoperation (a contact or proximate state, which will be described later)is performed on the touch detecting device 30 based on the controlsignal supplied from the controller 11 and on touch detection signalsVdet supplied from the touch detecting device 30 of the display devicewith a touch detection function 10. If a touch operation is detected,the touch detector 40 derives coordinates of the touch operation in atouch detection area, for example. The touch detector 40 includes anamplifier 42, an analog to digital converter (ADC) 43, a signalprocessor 44, a coordinate calculating circuit 45, a detection timingcontroller 46, an electric current measuring circuit 101, and a forcecalculating circuit 102, for example.

The amplifier 42 amplifies the touch detection signals Vdet suppliedfrom the touch detecting device 30. The amplifier 42 may include alow-pass analog filter that removes high-frequency components (noisecomponents) included in the touch detection signals Vdet to extract andoutput touch components.

The touch detecting device 30 operates based on the basic principle ofcapacitive touch detection to output the touch detection signals Vdet.The following describes the basic principle of touch detection in thedisplay apparatus with a touch detection function 1 according to thefirst embodiment with reference to FIGS. 1 to 4. FIG. 2 is a diagram forexplaining the basic principle of a capacitive touch detection systemand illustrates a state where a finger is neither in contact with nor inproximity to a touch detection electrode. FIG. 3 is a diagram forexplaining an example of an equivalent circuit in the state where afinger is neither in contact with nor in proximity to the touchdetection electrode as illustrated in FIG. 2. FIG. 4 is a diagram of anexample of waveforms of a drive signal and a touch detection signal.

As illustrated in FIG. 2, for example, a capacitance element C includesa pair of electrodes, that is, a drive electrode E1 and a touchdetection electrode E2 facing each other with a dielectric D interposedtherebetween. The capacitance element C accumulates electric chargesaccording to its capacitance, thereby forming an electric field. Asillustrated in FIG. 3, a first end of the capacitance element C iscoupled to an alternating-current (AC) signal source (drive signalsource) S, whereas a second end thereof is coupled to a voltage detector(touch detector) DET. The voltage detector DET is an integration circuitincluded in the amplifier 42 illustrated in FIG. 1, for example.

When the AC signal source S applies an AC rectangular wave Sg having apredetermined frequency (e.g., frequency on the order of severalkilohertz to several hundred kilohertz) to the drive electrode E1 (firstend of the capacitance element C), an output waveform (touch detectionsignal Vdet) is generated via the voltage detector DET coupled to thetouch detection electrode E2 (second end of the capacitance element C).The AC rectangular wave Sg corresponds to a touch drive signal Vcomt,which will be described later.

In a state where a finger is neither in contact with nor in proximity tothe touch detection electrode (non-contact state), an electric current Icorresponding to the capacitance value of the capacitance element Cflows with charge and discharge of the capacitance element C. Asillustrated in FIG. 4, the voltage detector DET converts change in theelectric current I in relation to the AC rectangular wave Sg into changein voltage (waveform V₀ indicated by the solid line).

By contrast, in a state where a finger is in contact with or inproximity to the touch detection electrode (contact state), capacitanceformed by the finger is in contact with or in proximity to the touchdetection electrode E2. In this state, fringe capacitance between thedrive electrode E1 and the touch detection electrode E2 is blocked. As aresult, the capacitance element C acts as a capacitance element having acapacitance value smaller than that in the non-contact state. Theelectric current I that changes depending on a change in the capacitanceelement C flows. As illustrated in FIG. 4, the voltage detector DETconverts change in the electric current I in relation to the ACrectangular wave Sg into change in voltage (waveform V₁ indicated by thedotted line). In this case, the waveform V₁ has amplitude smaller thanthat of the waveform V₀. An absolute value |ΔV| of voltage differencebetween the waveform V₀ and the waveform V₁ varies depending on aneffect of an external proximate object, such as a finger. To accuratelydetect the absolute value |ΔV| of the voltage difference between thewaveform V₀ and the waveform V₁, the voltage detector DET preferablyoperates having a period Reset for resetting charge and discharge of thecapacitance element synchronously with the frequency of the ACrectangular wave Sg by switching in the circuit.

The touch detecting device 30 illustrated in FIG. 1 sequentially scanseach detection block based on the drive signal Vcom (touch drive signalVcomt) supplied from the drive electrode driver 14, thereby performingtouch detection.

The touch detecting device 30 outputs the touch detection signals Vdetof respective detection blocks from a plurality of touch detectionelectrodes TDL, which will be described later, via the voltage detectorDET illustrated in FIG. 3. The touch detecting device 30 supplies thetouch detection signals Vdet to the ADC 43 of the touch detector 40.

The ADC 43 is a circuit that samples an analog signal that is outputfrom the amplifier 42 at a timing synchronized with the drive signalVcom to convert the analog signal into digital signal. If the touchdetector 40 is supplied with signals the intensity and thesignal-to-noise (S/N) ratio of which are sufficiently high for theprocessing performed by the signal processor 44, the amplifier 42 doesnot necessarily provided.

The signal processor 44 includes a digital filter that reduces frequencycomponents (noise components) having frequencies other than thefrequency at which the drive signal Vcom is sampled in the outputsignals from the ADC 43. The signal processor 44 is a logic circuit thatdetermines whether a touch operation is performed on the touch detectingdevice 30 based on the output signals from the ADC 43. The signalprocessor 44 performs processing of extracting only the voltage ofdifference caused by a finger. The voltage of difference caused by afinger corresponds to the absolute value |ΔV| of the difference betweenthe waveform V₀ and the waveform V₁. The signal processor 44 may performan arithmetic operation for averaging the absolute values |ΔV| perdetection block, thereby calculating the average of the absolute values|ΔV|. With this operation, the signal processor 44 can reduce an effectof noise. If the signal processor 44 fails to extract the voltage ofdifference, it is determined that an external proximate object isneither in contact with nor in proximity to the touch detecting device30. By contrast, if the signal processor 44 can extract the voltage ofdifference, it is determined that an external proximate object is incontact with or in proximity to the touch detecting device 30. Highervoltage of difference indicates that an external proximate object is inproximity to the touch detecting device 30 at a closer position or incontact therewith. As described above, the touch detector 40 can performtouch detection.

The signal processor 44 according to the first embodiment calculatesforce detected by force detectors based on the outputs from the touchdetection electrodes TDL serving as the touch detection electrode E2.Each of the force detectors is integrated with a corresponding one ofthe touch detection electrodes TDL. The output from the touch detectionelectrode TDL is an electric current Vi that is output in accordancewith application of voltage from the constant voltage circuit 15, forexample. The force detectors include the force detector 71 and the forcedetector 72, for example. The force in the present specificationincludes not only force per unit area but also simple pressing force.

The coordinate calculating circuit 45 is a logic circuit that derives,when the signal processor 44 detects a touch operation, the touch panelcoordinates of the touch operation. Specifically, for example, thecoordinate calculating circuit 45 derives the coordinates of a positioncorresponding to a combination of the touch detection electrode TDL andthe drive electrode COML, the touch detection electrode TDL beingdetermined to be in the contact state with an external proximate objectand outputting the touch detection signal Vdet, and the drive electrodeCOML being driven at the timing when the touch detection signal Vdet isoutput. The coordinates obtained by the coordinate calculating circuit45 are handled as the touch panel coordinates at which the touchoperation is detected. The coordinate calculating circuit 45 outputs asignal output Vout1 as the touch panel coordinates.

The detection timing controller 46 is a logic circuit that performscontrol such that the ADC 43, the signal processor 44, and thecoordinate calculating circuit 45 operate synchronously with oneanother.

The electric current measuring circuit 101 is a circuit that measuresthe value of the electric current Vi, which will be described later, andtransmits an output indicating the measurement result to the forcecalculating circuit 102. The force calculating circuit 102 is a logiccircuit that calculates distribution of force applied to the displayapparatus with a touch detection function 1 by a touch operation. Theforce calculating circuit 102 calculates the distribution of force basedon the value of the electric current Vi measured by the electric currentmeasuring circuit 101 and on previously stored information on thepositional relation between the force detectors (e.g., the forcedetectors 71 and 72) integrated with the corresponding touch detectionelectrodes TDL. By using the result of the arithmetic operation, theforce calculating circuit 102 can identify the touch panel coordinatesto which the largest force is applied by a touch operation, for example.The force calculating circuit 102 outputs a signal output Vout2 as theresult of the arithmetic operation.

FIG. 5 is a diagram of an example of a module provided with the displayapparatus with a touch detection function 1. As illustrated in FIG. 5,to mount the display apparatus with a touch detection function 1 on themodule, the drive electrode driver 14 may be provided on a grasssubstrate 21.

The display apparatus with a touch detection function 1 includes thedisplay device with a touch detection function 10, the drive electrodedriver 14, a chip on glass (COG) 19, and a printed circuit board PB, forexample. FIG. 5 schematically illustrates the positional relation inplanar view of the drive electrodes COML and the touch detectionelectrodes TDL intersecting with the drive electrodes COML in a gradeseparated manner. The drive electrodes COML, for example, extend in adirection along a first side of the display device with a touchdetection function 10. The touch detection electrodes TDL, for example,extend in a direction along a second side intersecting with the firstside of the display device with a touch detection function 10. Theoutput ends are coupled to the touch detector 40 provided outside themodule via a terminal such as the printed circuit board PB and othercomponents provided on the second side of the display device 10 with atouch detection function. The drive electrode driver 14 is provided atthe glass substrate 21. The COG 19 is a chip mounted on the glasssubstrate 21 and includes circuits required for a display operation,such as the controller 11, the gate driver 12, and the source driver 13illustrated in FIG. 1. The printed circuit board PB is a flexibleprinted circuit board provided with wiring, for example. The printedcircuit board PB, for example, serves as wiring that couples the touchdetection electrodes TDL to the touch detector 40, which is notillustrated in FIG. 5. The printed circuit board PB also serves aswiring that outputs the signal output Vout1 and the signal output Vout2to the outside.

The following describes an exemplary configuration of the display devicewith a touch detection function 10 in detail. FIG. 6 is a sectional viewof a schematic structure of the display device with a touch detectionfunction 10 according to the first embodiment. FIG. 7 is a circuitdiagram of arrangement of pixels in the display device with a touchdetection function 10 according to the first embodiment. The displaydevice with a touch detection function 10 includes a first substrate 2,a second substrate 3, and a liquid crystal layer 6. The second substrate3 faces the first substrate 2 in a direction perpendicular to thesurface of the first substrate 2. The liquid crystal layer 6 is arrangedbetween the first substrate 2 and the second substrate 3.

The first substrate 2 includes the glass substrate 21, a plurality ofpixel electrodes 22, a plurality of drive electrodes COML, and aninsulation layer 24. The pixel electrodes 22 are arranged in a matrix onthe upper side of the glass substrate 21. The drive electrodes COML areprovided between the glass substrate 21 and the pixel electrodes 22. Theinsulation layer 24 electrically insulates the pixel electrodes 22 fromthe drive electrodes COML. The glass substrate 21 is provided withthin-film transistor (TFT) elements Tr of the corresponding sub-pixelsSPix illustrated in FIG. 7 and wiring, such as signal lines SGL andscanning lines GCL. The signal line SGL supplies the pixel signal Vpixto the pixel electrode 22 illustrated in FIG. 6, and the scanning lineGCL drives the TFT element Tr. The signal line SGL extends on a planeparallel to the surface of the glass substrate 21 and supplies the pixelsignal Vpix for displaying an image on the pixel. The liquid crystaldisplay device 20 illustrated in FIG. 7 includes a plurality ofsub-pixels SPix arranged in a matrix. The sub-pixels SPix each includethe TFT element Tr and a display element (e.g., a liquid crystal elementLC). The TFT element Tr is a thin-film transistor and is an n-channelmetal oxide semiconductor (MOS) TFT in this example. One of the sourceand the drain of the TFT element Tr is coupled to the signal line SGL,the gate thereof is coupled to the scanning line GCL, and the other ofthe source and the drain thereof is coupled to a first end of the liquidcrystal element LC. The first end of the liquid crystal element LC iscoupled to the other of the source and the drain of the TFT element Tr,and a second end thereof is coupled to the drive electrode COML. Theliquid crystal element LC includes a corresponding one of the pixelelectrodes 22, for example, and the pixel electrode 22 is coupled to thedrain of the TFT element Tr. The liquid crystal elements LC are coupledto the drive electrodes COML via the insulation layer 24 and the liquidcrystal layer 6. The sub-pixels SPix are driven by electric chargessupplied to the pixel electrodes 22 and the drive electrodes COML. Thepixel electrodes 22 and the drive electrodes COML thus serve aselectrodes used to drive the sub-pixels SPix. The drive electrodes COML,the insulation layer 24, and the pixel electrodes 22 according to thepresent embodiment are layered in this order on the glass substrate 21.The configuration is not limited thereto, and the pixel electrodes 22,the insulation layer 24, and the drive electrodes COML may be layered inthis order on the glass substrate 21. Alternatively, the pixelelectrodes 22 and the drive electrodes COML may be provided in a singlelayer with the insulation layer 24 interposed therebetween.

The sub-pixel SPix illustrated in FIG. 7 is coupled to other sub-pixelsSPix belonging to the same row in the liquid crystal display device 20by the scanning line GCL. The scanning line GCL is coupled to the gatedriver 12 and supplied with the scanning signal Vscan from the gatedriver 12. The sub-pixel SPix is coupled to other sub-pixels SPixbelonging to the same column in the liquid crystal display device 20 bythe signal line SGL. The signal line SGL is coupled to the source driver13 and supplied with the pixel signal Vpix from the source driver 13.The sub-pixel SPix is also coupled to the other sub-pixels SPixbelonging to the same row in the liquid crystal display device 20 by thedrive electrode COML. The drive electrode COML is coupled to the driveelectrode driver 14 and supplied with the drive signal Vcom from thedrive electrode driver 14.

The gate driver 12 illustrated in FIG. 1 applies the scanning signalVscan to the gates of the TFT elements Tr of the pixels Pix via thescanning line GCL illustrated in FIG. 7. As a result, the gate driver 12sequentially selects, as a target of display drive, sub-pixels SPix thatshare one scanning line GCL in one row (one horizontal line) out of thesub-pixels SPix arranged in a matrix in the liquid crystal displaydevice 20. The source driver 13 illustrated in FIG. 1 supplies the pixelsignals Vpix to the sub-pixels SPix sequentially selected by the gatedriver 12 via the signal lines SGL illustrated in FIG. 7. Thesesub-pixels SPix perform display output based on the supplied pixelsignals Vpix. The drive electrode driver 14 illustrated in FIG. 1applies the drive signal Vcom, thereby driving the drive electrodes COMLin each block composed of a predetermined number of drive electrodesCOML. The extending directions of the drive electrodes COML and thetouch detection electrodes TDL may be appropriately changed. While thedrive electrodes COML illustrated in FIG. 7 extend in the same directionas the aligning direction of the sub-pixels SPix constituting the pixelPix, the extending direction of the drive electrodes COML may beorthogonal to the aligning direction. The touch detection electrodes TDLand the drive electrodes COML simply need to overlap in an intersectingmanner, and they need not intersect with each other at right angles inplanar view.

The gate driver 12 drives to sequentially linearly scan the scanninglines GCL in the liquid crystal display device 20 in a time-divisionmanner. The drive electrode driver 14 applies the drive signal Vcom tothe block including the drive electrodes COML corresponding to thepositions provided with the sub-pixels SPix supplied with the pixelsignals Vpix from the source driver 13.

The drive electrodes COML according to the first embodiment serve notonly as drive electrodes of the liquid crystal display device 20 butalso as drive electrodes of the touch detecting device 30. FIG. 8 is aperspective view of an exemplary configuration of the drive electrodesand the touch detection electrodes in the display device with a touchdetection function according to the first embodiment. The driveelectrodes COML illustrated in FIG. 8 face the pixel electrodes 22 inthe direction perpendicular to the surface of the glass substrate 21 asillustrated in FIG. 6. The touch detecting device 30 includes the driveelectrodes COML provided in the first substrate 2 and the touchdetection electrodes TDL provided in the second substrate 3. The touchdetection electrodes TDL are stripe electrode patterns extending in adirection intersecting with the extending direction of the electrodepatterns of the drive electrodes COML. The touch detection electrodesTDL face the drive electrodes COML in the direction perpendicular to thesurface of the glass substrate 21. The electrode patterns of the touchdetection electrodes TDL are coupled to the input side of the amplifier42 of the touch detector 40. The electrode patterns of the driveelectrodes COML and the touch detection electrodes TDL intersecting witheach other form capacitance at the intersections. As described above,the display apparatus with a touch detection function 1 includes thedrive electrodes (drive electrodes COML) that are not in contact withthe touch detection electrodes (touch detection electrodes TDL) to formcapacitance between the touch detection electrodes and the driveelectrodes. The touch detection electrodes TDL or the drive electrodesCOML (drive electrode blocks) do not necessarily have a shape of stripepatterns in which a plurality of electrodes (blocks) are separated fromeach other. The touch detection electrodes TDL or the drive electrodesCOML (drive electrode blocks) may have a comb shape, for example. Thetouch detection electrodes TDL or the drive electrodes COML (driveelectrode blocks) simply need to have a shape in which a plurality ofelectrodes are separated from each other. The shape of slits thatseparate the drive electrodes COML may be a straight line or a curvedline.

With this configuration, to perform a touch detection operation in thetouch detecting device 30, the drive electrode driver 14 drives tosequentially scan the drive electrode blocks in a time-division manner.As a result, each detection block of the drive electrodes COML issequentially selected in a scanning direction Scan. The touch detectionelectrodes TDL each output the touch detection signal Vdet. The touchdetecting device 30 thus performs touch detection on one detectionblock. In other words, the drive electrode blocks correspond to thedrive electrode E1 in the basic principle of touch detection, whereasthe touch detection electrodes TDL correspond to the touch detectionelectrode E2. The touch detecting device 30 detects a touch operationaccording to the basic principle. The touch detecting device 30 thusperforms touch detection on a screen side (display surface side) of thedisplay device (liquid crystal display device 20). As illustrated inFIG. 8, the electrode patterns intersecting with each other serve as acapacitive touch sensor formed in a matrix. The display apparatus with atouch detection function 1 scans the entire touch detection surface ofthe touch detecting device 30 provided to cover the display surface onwhich display output is performed in a display area 20 a. With thisconfiguration, the display apparatus with a touch detection function 1can detect a position where an external proximate object is in contactwith or in proximity to the touch detection surface.

The liquid crystal layer 6 modulates light passing therethroughdepending on the state of an electric field. The liquid crystal layer 6,for example, is a liquid crystal display device including liquidcrystals driven in a lateral electric-field mode, such as the in-planeswitching (IPS) mode including the fringe field switching (FFS) mode. Anorientation film may be provided between the liquid crystal layer 6 andthe first substrate 2 and between the liquid crystal layer 6 and thesecond substrate 3 illustrated in FIG. 6.

The second substrate 3 includes a glass substrate 31 and a color filter32 provided on one surface of the glass substrate 31. The touchdetection electrodes TDL serving as the detection electrodes of thetouch detecting device 30 are provided on the other surface of the glasssubstrate 31. A polarization plate 35 is provided on the touch detectionelectrodes TDL. While the substrates in the first substrate and thesecond substrate according to the first embodiment are glass substrates,the present embodiment is not limited thereto. The substrates in thefirst substrate and the second substrate may be film substrates, forexample.

The color filter 32 illustrated in FIG. 6 has color areas colored withthree colors of red (R), green (G), and blue (B), for example, andcyclically arranged. Color areas 32R, 32G, and 32B (refer to FIG. 7)colored with the three colors of R, G, and B are associated with thecorresponding sub-pixels SPix illustrated in FIG. 7. A group of thecolor areas 32R, 32G, and 32B constitutes one pixel Pix. The pixels Pixare arranged in a matrix in the direction parallel to the scanning linesGCL and the direction parallel to the signal lines SGL to serve as thedisplay area 20 a.

The color filter 32 faces the liquid crystal layer 6 in the directionperpendicular to the glass substrate 21. Each sub-pixel SPix can displaya single color. The liquid crystal display device 20 performs displayoutput using the pixels Pix composed of the sub-pixels SPix colored withdifferent colors by the color filter 32, thereby displaying an image. Inother words, the liquid crystal display device 20 includes the pixelsPix that display an image. The color filter 32 may have anothercombination of colors as long as they are different colors. The numberof types of colors is not limited to three and may be four or more. Thecolor filter 32 may include an area with no color or an area with nocolor filter 32. In other words, a sub-pixel SPix not colored with thecolor filter 32 may be provided.

The following describes a configuration that performs force detectionand a mechanism of the force detection. FIG. 9 is a schematic wiringdiagram of exemplary arrangement of the force detectors 71 and 72provided in the display apparatus with a touch detection function 1. Thedisplay apparatus with a touch detection function 1 includes the forcedetectors 71 and 72. Specifically, as illustrated in FIG. 9, forexample, the force detectors 71 and 72 are provided at ends of the touchdetection electrodes TDL and on opposite sides of the display area 20 a.More specifically, the force detectors 71 and 72 are provided outsidethe display area 20 a as components connected to wiring that couples thecorresponding touch detection electrodes TDL to the touch detector 40(refer to FIG. 5). Thus, the force detectors 71 and 72 are integratedwith the corresponding touch detection electrodes TDL and thecorresponding wiring. In FIG. 9 and other figures, U denotes anelectrical coupling end on the side provided with the touch detectionelectrode TDL with respect to the force detectors 71 and 72. In FIG. 9and other figures, Q denotes a coupling line on the side not providedwith the touch detection electrode TDL with respect to the forcedetectors 71 and 72. In FIG. 9 and other figures, U and Q each have asubscript. One combination of the force detector (force detector 71 or72) and the touch detection electrode TDL coupled to the coupling end Uand the coupling line Q having the same subscript serves as oneconfiguration. In FIG. 9 and other figures, T denotes the configurationincluding the force detector (force detector 71 or 72) and the touchdetection electrode TDL provided between the coupling end U and thecoupling line Q. T has the same subscript as those of the coupling end Uand the coupling line Q. FIG. 9 illustrates a plurality of coupling endsU₁, U₂, . . . , U₁₄, a plurality of coupling lines Q₁, Q₂, . . . , Q₁₄,and configurations T₁ and T₂. These reference numerals do not indicatethe specific number of the force detectors (force detector 71 or 72) andthe specific number of the touch detection electrodes TDL. The forcedetector 72 and the touch detection electrode TDL provided between thecoupling end U₃ and the coupling line Q₃, for example, are assumed to bea configuration T₃, which is not illustrated. This rule is also appliedto the configuration (T) provided between the coupling end U and thecoupling line Q having a subscript of 4 or larger. The coupling ends U₁,U₂, . . . may be referred to as the coupling end U when they need notparticularly be distinguished from one another. The coupling lines Q₁,Q₂, . . . may be referred to as the coupling line Q when they need notparticularly be distinguished from one another. The configurations T₁,T₂, . . . may be referred to as the configuration T when they need notparticularly be distinguished from one another.

FIG. 10 is a diagram of an example of a specific configuration of theforce detector 71 and a portion near the force detector 71. FIG. 11 is adiagram of an example of a specific configuration of the force detector72 and a portion near the force detector 72. The force detector 71 hasstrain detection patterns 71 a and folded patterns 71 b. The forcedetector 72 has strain detection patterns 72 a and folded patterns 72 b.The strain detection patterns 71 a are a plurality of wiring patternsextending in parallel with a detection direction. The folded patterns 71b are wiring patterns that couple strain detection patterns 71 aadjacent to each other in an intersection direction orthogonal to thedetection direction and along the plate surface of the display apparatuswith a touch detection function 1. The strain detection patterns 72 aare a plurality of wiring patterns extending in parallel with adetection direction. The folded patterns 72 b are wiring patterns thatcouple strain detection patterns 72 a adjacent to each other in anintersection direction orthogonal to the detection direction and alongthe plate surface of the display apparatus with a touch detectionfunction 1. The extending direction of the strain detection patterns 71a is different from the extending direction of the strain detectionpatterns 72 a. Two folded patterns 71 b couple a strain detectionpattern 71 a with two strain detection patterns 71 a adjacent to thestrain detection pattern 71 a in a manner sandwiching it therebetween.The positions of the two folded patterns 71 b are opposite to eachother. That is, the strain detection pattern 71 a is coupled to one ofthe two strain detection patterns 71 a by one folded pattern 71 bpositioned at a first end in the detection direction. The straindetection pattern 71 a is also coupled to the other of the two straindetection patterns 71 a by another folded pattern 71 b positioned at asecond end in the detection direction. In other words, the foldedpatterns 71 b include a first folded pattern 71 b and a second foldedpattern 71 b. The first folded pattern 71 b is arranged on the first endin the detection direction, and the second folded pattern 71 b isarranged on the second end in the detection direction. The first foldedpattern 71 b and the second folded pattern 71 b are arranged alternatelyin the intersection direction orthogonal to the detection direction.Assuming that three strain detection patterns 71 a arrangedconsecutively are denoted by a first strain detection pattern 71 a, asecond strain detection pattern 71 a, and a third strain detectionpattern 71 a. The second strain detection pattern 71 a between the firstand the third strain detection patterns 71 a is coupled to the firststrain detection pattern 71 a by the first folded pattern 71 b. Thesecond strain detection pattern 71 a is coupled to the third straindetection pattern 71 a by the second folded pattern 71 b. The straindetection patterns 72 a and folded patterns 72 b of the force detector72 are arranged in the similar manner to the strain detection patterns71 a and folded patterns 71 b of the force detector 71. With the straindetection patterns 71 a and 72 a and the folded patterns 71 b and 72 bhaving the coupling relation described above, each of the forcedetectors 71 and 72 is provided as a wiring pattern including the straindetection patterns extending in the detection direction andconsecutively aligned in the intersection direction.

The force detectors 71 and 72 each serve as a strain gauge that detectsa strain in the display apparatus with a touch detection function 1.Specifically, when force applied by a touch operation generates a strainin the plate surface of the display apparatus with a touch detectionfunction 1, the force detectors 71 and 72 detect the strain. The degreeof the strain varies depending on the force applied by the touchoperation. The force detectors 71 and 72 detect a strain in the displayapparatus with a touch detection function 1, thereby detecting forceapplied to the display apparatus with a touch detection function 1 by atouch operation. More specifically, the electrical resistance value ofthe force detectors 71 and 72 changes depending on the degree of thestrain. Consequently, the display apparatus with a touch detectionfunction 1 can detect force (force applied by a touch operation), whichgenerates a strain in the display apparatus with a touch detectionfunction 1, based on a change in the electrical resistance value of theforce detectors 71 and 72. In the following description, a term “forcedetection” indicates detection of presence of force (force applied by atouch detection) that generates a strain in the display apparatus with atouch detection function 1 and detection of the magnitude of force usingthe force detectors 71 and 72. As described above, the display apparatuswith a touch detection function 1 includes the strain gauges (e.g., theforce detectors 71 and 72), each of which is integrated with acorresponding one of the touch detection electrodes (e.g., the touchdetection electrodes TDL) provided along the touch detection surface.

The force detectors 71 and 72 mainly detect a strain generated in thedetection direction. The detection direction of the force detector 71according to the first embodiment is different from that of the forcedetector 72. The detection direction of the force detector 71, forexample, is the same as the extending direction of the drive electrodesCOML. By contrast, the detection direction of the force detector 72 is adirection orthogonal to the extending direction of the drive electrodesCOML and along the plate surface of the display apparatus with a touchdetection function 1. With a plurality of force detectors 71 and 72, theforce distribution (e.g., to which portion larger force is applied) onthe touch detection surface can be determined based on the respectivestrain amounts.

The folded patterns 71 b and 72 b of the force detectors 71 and 72 havehigher rigidity than that of the strain detection patterns 71 a and 72 aagainst a strain in the intersection direction. Specifically, the foldedpatterns 71 b and 72 b have a rectangular shape. The folded patterns 71b and 72 b are provided such that the degree of a change in theelectrical resistance of the folded patterns 71 b and 72 b generatedwhen a strain occurs in the intersection direction is smaller than achange in the electrical resistance of the strain detection patterns 71a and 72 a generated when a strain occurs in the detection direction.The shape of the folded patterns 71 b and 72 b is not limited to arectangular shape, and the folded patterns 71 b and 72 b may haveanother shape capable of reducing the electrical resistance.

The force detectors 71 and the force detectors 72 are alternatelyarranged. Specifically, as illustrated in FIG. 9, for example, the forcedetectors 71 and the force detectors 72 are alternately arranged in theextending direction of the drive electrodes COML in areas included in aframe area outside the display area 20 a, the longitudinal direction ofthe areas extending in the extending direction of the drive electrodesCOML. In the relation between the touch detection electrodes TDL alignedin the extending direction of the drive electrodes COML and the forcedetectors 71 and 72, a predetermined number of the force detectors 71that are consecutively aligned and a predetermined number of the forcedetectors 72 that are consecutively aligned are alternately arrangedwith respect to the touch detection electrodes TDL, each of the forcedetectors 71 and 72 being coupled with a corresponding one of the touchdetection electrodes TDL. The predetermined number is two in FIG. 9, forexample.

To detect force, there has been developed a method of measuring theelectrical resistance value based on an electric current (e.g., theelectric current Vi) caused to flow by voltage supplied to the forcedetectors 71 and 72, for example. The force calculating circuit 102calculates force based on the measurement of the electrical resistancevalue. In other words, the touch detector 40 serves as a detector thatdetects force based on the electrical resistance in the touch detectionelectrodes (e.g., the touch detection electrodes TDL) each of which isintegrated with a corresponding one of the strain gauges (e.g., theforce detectors 71 and 72).

FIG. 12 is a block diagram of an example of a functional configurationof a circuit that detects force. As illustrated in FIG. 12, the couplingends U₁, U₂, . . . are coupled to the constant voltage circuit 15 via aselector switch circuit SEL. The selector switch circuit SEL is aswitching circuit that selectively couples the coupling ends U₁, U₂, . .. to the constant voltage circuit 15. The selector switch circuit SELmay be provided as part of the constant voltage circuit 15 or may be anindependent circuit that operates under the control of the controller11.

The constant voltage circuit 15 supplies constant voltage Vt to oneconfiguration T (e.g., one of the configurations T₁, T₂, . . . ) coupledthereto via the selector switch circuit SEL. The constant voltagecircuit 15 applies the voltage from the coupling end U side to which theselector switch circuit SEL is coupled. The coupling end U side coupledwith the selector switch circuit SEL is a side on which the touchdetection electrode TDL is provided with respect to the force detector(force detector 71 or 72). While the voltage is applied to aconfiguration T from one end (coupling end U) thereof in FIGS. 9 and 12and other figures, the voltage may be applied to a configuration T fromboth ends (e.g., the coupling end U and the coupling line Q) thereof.The configuration T generates the electric current Vi in relation to theconstant voltage Vt and outputs it to the electric current measuringcircuit 101. The electric current measuring circuit 101 measures thevoltage value of the electric current Vi and transmits an outputindicating the measurement result to the force calculating circuit 102.The configuration T includes the force detector (force detector 71 or72), and the electric resistance value changes depending on a straingenerated by force applied to the touch detection surface. In otherwords, the magnitude of the voltage value of the electric current Vivaries depending on the presence or absence of force and the magnitudeof force when the force is present. Based on the value of the electriccurrent Vi measured by the electric current measuring circuit 101, theforce calculating circuit 102 calculates force detected at the positionof the force detector (force detector 71 or 72) included in theconfiguration T.

The selector switch circuit SEL performs a switching operation atregular time intervals, such that configuration T to which the constantvoltage Vt is supplied is shifted one by one. The selector switchcircuit SEL, for example, may scan the configurations T in order of thesubscript or another order. The configurations T each generate theelectric current Vi in relation to the constant voltage Vt and output itto the electric current measuring circuit 101. The electric currentmeasuring circuit 101 individually measures the voltage values of theelectric currents Vi from the corresponding configurations T andtransmits outputs each of which indicates the measurement result on acorresponding one of the configurations T to the force calculatingcircuit 102. The force calculating circuit 102 calculates thedistribution of force applied to the display apparatus with a touchdetection function 1 by a touch operation, based on the force indicatedby the voltage value of the electric current Vi that is output from eachof the configurations T and on the previously stored information on thepositional relation between the force detectors (e.g., the forcedetectors 71 and 72) integrated with the corresponding touch detectionelectrodes TDL. In a case where the calculation of the forcedistribution is performed, the following two timings are set to bedifferent from each other: the timing of touch detection performed bythe touch detection electrodes TDL that perform capacitive touchdetection, and the timing of supplying voltage for force detection tothe force detectors 71 and 72.

In the first embodiment, the drive electrodes COML are used for bothdisplay drive and touch detection. Thus, the timing of display drive isset to be different from the timing of touch detection. While thosetimings are controlled by the detection timing controller 46 under thecontrol of the controller 11, a dedicated component that controls thetimings may be provided.

FIG. 13 is a timing chart schematically illustrating the relationbetween a display drive timing, a touch detection timing, and a forcedetection timing in the display apparatus with a touch detectionfunction 1. As described above, the timing of display drive is differentfrom the timing of touch detection. The display apparatus with a touchdetection function 1 of the first embodiment employs an intermittentdriving method in which display drive and touch detection arealternately performed. As described above, the timing of touch detectionis different from the timing of force detection. By contrast, the timingof display drive need not be different from the timing of forcedetection. Thus, in the first embodiment, display drive and forcedetection are performed at the same time. Specifically, at the timing ofdisplay drive, the constant voltage circuit 15 supplies voltage to thetouch detection electrodes TDL and the force detectors 71 and 72. Bycontrast, at the timing of touch detection, the drive electrode COML andthe touch detection electrode TDL form capacitance in the capacitanceelement C used for touch detection according to the drive signal Vcomsupplied to the drive electrode COML.

In the electrodes of the display apparatus with a touch detectionfunction 1, that is, in the drive electrodes COML, the touch detectionelectrodes TDL, the force detectors 71 and 72, and other electrodes, theelectrical resistance changes depending on temperature. By consideringthe relation between the electrodes and the temperature, touch detectionand force detection can be performed more accurately. The displayapparatus with a touch detection function 1 may include a temperaturedetector, for example. In this case, the signal processor 44 or anothercomponent may perform correction based on the temperature detected bythe temperature detector in the arithmetic operation thereof.

The circuit configuration that detects force using the force detectors71 and 72 may be appropriately changed. FIG. 14 is a block diagram ofanother example of a functional configuration of the circuit thatdetects force. As illustrated in FIG. 14, the circuit configurationrelated to force detection may have a configuration in which theconfiguration T including the force detector (force detector 71 or 72)is used as one electrical resistor the resistance value of which isunknown among four electrical resistors included in a Wheatstone bridgeH. Specifically, the Wheatstone bridge H includes electrical resistorsR₁, R₂, and R₃ and a plurality of configurations T. The resistancevalues of the electrical resistors R₁, R₂, and R₃ are known. Theconfigurations T are selectively coupled to the other electricalresistors included in the Wheatstone bridge H by the selector switchcircuit SEL. In other words, the configuration T coupled by the selectorswitch circuit SEL is used as one electrical resistor, the value ofwhich is unknown, among the four electrical resistors included in theWheatstone bridge H. More specifically, in the Wheatstone bridge H, theconfiguration T is coupled to the electrical resistors R₂ and R₃, forexample. The electrical resistance R₁ is coupled to the ends of theelectrical resistors R₂ and R₃ in the Wheatstone bridge H, the ends notbeing coupled to the configuration T.

The Wheatstone bridge H is coupled to the constant voltage circuit 15and an electrical resistance measuring circuit 101A. The electricalresistance measuring circuit 101A is provided instead of the electriccurrent measuring circuit 101 to measure the electrical resistance valueof the Wheatstone bridge H. Specifically, the constant voltage circuit15 is coupled to the Wheatstone bridge H at two points between theconfiguration T and the electrical resistor R₃ and between theelectrical resistor R₁ and the electrical resistance R₂ to supply theconstant voltage. The electrical resistance measuring circuit 101A iscoupled to the Wheatstone bridge H at two points between theconfiguration T and the electrical resistor R₂ and between theelectrical resistor R₁ and the electrical resistor R₃ to measure theelectrical resistance value. The electrical resistance value measured bythe electrical resistance measuring circuit 101A changes depending on achange in the electrical resistance value of the force detector (forcedetector 71 or 72) of the configuration T. The change in the electricalresistance value of the force detector (force detector 71 or 72) iscaused depending on a strain generated by force applied to the touchdetection surface. Consequently, the electrical resistance valuemeasured by the electrical resistance measuring circuit 101A indicatesthe force that generates a strain in the force detector 71 or 72. Anoutput indicating the electrical resistance value measured by theelectrical resistance measuring circuit 101A is transmitted to the forcecalculating circuit 102. Based on the force indicated by the electricalresistance value and on the previously stored information on thepositional relation between the force detectors (e.g., the forcedetectors 71 and 72) integrated with the corresponding touch detectionelectrodes TDL, the force calculating circuit 102 calculates thedistribution of force applied to the display apparatus with a touchdetection function 1 by a touch operation.

While the configurations T share one Wheatstone bridge H using theselector switch circuit SEL in FIG. 14, each of the configurations T maybe individually provided with a corresponding one of Wheatstone bridgesH.

FIG. 15 is a timing chart schematically illustrating the relationbetween the display drive timing, the touch detection timing, and theforce detection timing in a case where touch detection and forcedetection are performed in parallel in the same period. In thedescription with reference to FIG. 13, the timing of touch detectionperformed by the touch detection electrodes TDL that perform capacitivetouch detection is different from the timing of supplying voltage forforce detection to the force detectors 71 and 72. Alternatively, thesetimings may be the same timing. In other words, touch detection andforce detection may be performed in parallel in the same period.

FIG. 16 is a block diagram of an example of a functional configurationof the circuit that detects force in a case where touch detection andforce detection are performed in parallel in the same period. In theexample illustrated in FIG. 16, a voltage application circuit 15A isprovided instead of the constant voltage circuit 15. The voltageapplication circuit 15A outputs pulses (square wave) from the couplingline Q side to the configuration T, thereby applying voltage. An output(touch detection signal Vdet) from the configuration T to which thevoltage is applied is received by the touch detector 40 and a differencedetector 101B coupled to the configuration T via the selector switchcircuit SEL. The difference detector 101B includes an amplifier AMP, acomparator COMP, and a counter COUN, for example. The amplifier AMPamplifies the output from the configuration T. The comparator COMPoutputs a signal corresponding to a result of comparison between theoutput from the amplifier and reference voltage TH (refer to FIG. 17)serving as a threshold. The counter COUN counts the period in which thesignal is output from the comparator COMP.

FIG. 17 is a diagram of an example of the relation between a voltagewaveform of a pulse that is output from the voltage application circuit15A, an output from the amplifier AMP, and an output from the comparatorCOMP depending on the output from the amplifier AMP. An output from theconfiguration T generated in response to the pulses from the voltageapplication circuit 15A is amplified by the amplifier AMP and comparedwith the reference voltage TH by the comparator COMP. The output fromthe configuration T varies depending on whether a strain is generated byforce in the force detector (force detector 71 or 72). Specifically, anoutput PE₁ obtained when a strain is generated by force has a largertime constant in rise and fall of the output than that of an output PN₁obtained when no strain is generated. This is because, when a strain isgenerated by force in the force detector (force detector 71 or 72), theelectrical resistance in the force detector increases. As a result, inthe relation with respect to the reference voltage TH, the output PE₁obtained when a strain is generated by force is different from theoutput PN₁ obtained when no strain is generated as follows: the outputPE₁ exceeds the reference voltage TH at a timing later than that of theoutput PN₁ and falls below the reference voltage TH at a timing earlierthan that of the output PN₁, for example. Consequently, an output PE₂that is output from the comparator COMP when a strain is generated byforce is different in the output pattern from an output PN₂ that isoutput when no strain is generated as follows: the output PE₂ starts ata timing later than that of the output PN₂ and ends at a timing earlierthan that of the output PN₂, for example. The difference detector 101Boutputs a result of counting performed by the counter COUN to the forcecalculating circuit 102. Based on the result of force detectionindicated by the count result and on the previously stored informationon the positional relation between the force detectors (e.g., the forcedetectors 71 and 72) integrated with the corresponding touch detectionelectrodes TDL, the force calculating circuit 102 calculates thedistribution of force applied to the display apparatus with a touchdetection function 1 by a touch operation. In the configurationillustrated in FIG. 17, the touch detector 40 may perform touchdetermination using the output from the amplifier AMP or the output fromthe comparator COMP.

As described above, the display apparatus with a touch detectionfunction 1 of the first embodiment includes the strain gauge (e.g., theforce detector 71 or 72) integrated with the touch detection electrode(e.g., the touch detection electrode TDL) provided along the touchdetection surface. As a result, the configuration that performs touchdetection can be integrated with the configuration that performs forcedetection. Consequently, the first embodiment can detect force with aconfiguration integrated with a component used for another configuration(configuration related to touch detection).

The display apparatus with a touch detection function 1 of the firstembodiment detects force based on the electrical resistance in the touchdetection electrode integrated with the strain gauge. Consequently, thefirst embodiment can secure the accuracy of force detection.

Second Embodiment

The following describes an embodiment (second embodiment) part of theconfiguration of which is different from that of the first embodimentwith reference to FIGS. 18 to 23. In the description of the secondembodiment, components similar to those of the first embodiment aredenoted by the same reference numerals, and explanation thereof may beomitted.

FIG. 18 is a diagram of an example of a configuration of the forcedetector 71 and a portion near the force detector 71 according to thesecond embodiment. FIG. 19 is a diagram of an example of a specificconfiguration of the force detector 72 and a portion near the forcedetector 72 according to the second embodiment. While the touchdetection electrodes TDL are each schematically represented by one solidline in FIG. 9, the touch detection electrodes TDL according to thesecond embodiment each have two electrical systems. In the descriptionof the two electrical systems, one of the two electrical systems may bereferred to as a “first system RX1”, whereas the other thereof may bereferred to as a “second system RX2”. The specific arrangement of theforce detectors 71 and 72 according to the second embodiment is the sameas that illustrated in FIG. 9, for example. The various methods fordetecting force described with reference to FIGS. 12 to 17 are alsoapplicable to the second embodiment.

As illustrated in FIGS. 18 and 19, the first system RX1 has the samestructure as that of the touch detection electrode TDL according to thefirst embodiment. In other words, each of the force detectors 71 and 72according to the second embodiment is provided outside the display area20 a as a component connected to wiring that couples the touch detectionelectrode TDL of the first system RX1 to the touch detector 40 (refer toFIG. 5). Each of the force detectors 71 and 72 is integrated with thetouch detection electrode TDL of the first system RX1 and the wiring.The second system RX2 does not have the force detector 71 or the forcedetector 72. Specifically, as illustrated in FIGS. 18 and 19, wiringthat couples the touch detection electrode TDL of the second system RX2to the touch detector 40 (refer to FIG. 5) is an L-shaped wiring patternrimming the area provided with the force detectors 71 and 72. Thus, inthe second embodiment, both the touch detection electrode (first systemRX1) integrated with the strain gauge and the touch detection electrode(second system RX2) not provided with the strain gauge are arranged.

FIG. 20 is a diagram schematically illustrating an exemplaryconfiguration that selectively operates the two systems. FIG. 20 andother figures do not illustrate the amplifier 42. The first system RX1and the second system RX2 according to the second embodiment can sharethe ADC 43. Specifically, as illustrated in FIG. 20, for example, aswitch SW1 may be provided on a coupling path between the ADC 43 and thefirst and second systems RX1 and RX2. The switch SW1 can switch betweena first mode in which the ADC 43 is coupled to the first system RX1 anda second mode in which the ADC 43 is coupled to the second system RX2.The switch SW1 switches the coupling mode of the ADC 43 between thefirst mode and the second mode at a switching timing controlled by thedetection timing controller 46, for example.

The display apparatus with a touch detection function 1 of the secondembodiment uses both the first system RX1 and the second system RX2,thereby performing touch detection and force detection in parallel.Specifically, the display apparatus with a touch detection function 1 ofthe second embodiment uses the output from the second system RX2 nothaving the force detector 71 or the force detector 72 as standards(reference). The display apparatus with a touch detection function 1 ofthe second embodiment can perform force detection based on the relationbetween the output from the second system RX2 and the output from thefirst system RX1 that can change depending on the presence of force.

FIG. 21 is a diagram schematically illustrating the relation betweendrive timings of the two systems, coordinate calculation based on theresults of touch detection performed by the two systems, and forcecalculation based on the results of touch detection performed by the twosystems. As illustrated in the top figure in FIG. 21, the first systemRX1 and the second system RX2 are driven at different timings. A timingat which the first system RX1 of the touch detection electrode TDL formscapacitance C3 with the drive electrode COML and outputs the touchdetection signal Vdet is different from a timing at which the secondsystem RX2 of the touch detection electrode TDL forms capacitance C3 andoutputs the touch detection signal Vdet.

Both the touch detection signals Vdet that are output from the firstsystem RX1 and the second system RX2 can be used for touch detection.The exclusive use of the first system RX1 and the second system RX2 doesnot reduce the touch detection period. A period (RX1+RX2) in which oneof the first system RX1 and the second system RX2 can form thecapacitance C3 with the drive electrodes COML serve as the touchdetection period.

FIG. 22 is a diagram schematically illustrating an example of differencebetween an output from the second system RX2 and an output from thefirst system RX1 obtained when no force is applied. FIGS. 23 and 24 arediagrams schematically illustrating an example of difference between theoutput from the second system RX2 and the output from the first systemRX1 obtained when force is applied. Force can be calculated based on thedifference (RX2 t 1−RX1 t 1) between the output from the second systemRX2 and the output from the first system RX1. As illustrated in FIGS. 9,18, and 19, the first system RX1 and the second system RX2 of the touchdetection electrodes TDL are arranged at substantially the same positionand perform touch detection at substantially the same position. When noforce is applied by a touch operation, the touch detection signal Vdetof the first system RX1 is substantially the same as the touch detectionsignal Vdet of the second system RX2. If the touch detection period isthe same, synthesized an output obtained by synthesizing an outputpattern (RX2 t 1) of the touch detection signal Vdet that is output fromthe second system RX2 from the start timing to the end timing of touchdetection and an inverted output pattern (−RX1 t 1) of the touchdetection signal Vdet that is output from the first system RX1 from thestart timing to the end timing of touch detection cancels out theoutputs as illustrated in FIG. 22. In other words, if the synthesizedoutput indicating the difference (RX2 t 1−RX1 t 1) between the outputfrom the second system RX2 and the output from the first system RX1 issubstantially 0 or equivalent to 0, it is determined that no force isapplied by a touch operation as a result of force detection. Bycontrast, when force is applied by a touch operation, a strain isgenerated in the force detectors 71 and 72. In this case, the electricalresistance in the first system RX1 increases compared with the casewhere no force is applied. As a result, the inverted output pattern(−RX1 t 1) of the touch detection signal Vdet that is output from thefirst system RX1 from the start timing to the end timing of touchdetection changes depending on the increase in the electricalresistance. Specifically, as illustrated in FIG. 23, the wave height(resistance value equivalent) of the inverted output pattern (−RX1 t 1)of the touch detection signal Vdet that is output from the first systemRX1 is higher than that of the output pattern (RX2 t 1) of the touchdetection signal Vdet that is output from the second system RX2, forexample. Thus, the inverted output pattern (−RX1 t 1) is different inthe wave height (resistance value equivalent) from the output pattern(RX2 t 1). Let us assume a case where the display apparatus with a touchdetection function 1 of the second embodiment uses the output from thecomparator COMP described with reference to FIG. 17. In this case, asillustrated in FIG. 24, the rising period in the waveform of theinverted output pattern (−RX1 t 1) of the touch detection signal Vdet isshorter than that of the output pattern (RX2 t 1), for example. Thus,the rising period in the waveform of the inverted output pattern (−RX1 t1) is different from that of the output pattern (RX2 t 1). As a result,the synthesized output indicating the difference (RX2 t 1−RX1 t 1)between the output from the second system RX2 and the output from thefirst system RX1 has positive and negative signal changes as illustratedin FIGS. 23 and 24, for example. In other words, if the synthesizedoutput is significantly larger than 0, it is determined that force isapplied by a touch operation as a result of force detection. As theapplied force increases, the synthesized output increases. Consequently,the magnitude of force can be measured based on the degree of the changein the synthesized output with respect to the synthesized outputobtained when no force is applied.

According to the second embodiment, the signal processor 44 calculatesforce based on the difference between the touch detection signals Vdetthat are output from the two systems. Based on the calculated force, theforce calculating circuit 102 calculates the distribution of force. Inother words, the touch detector 40 according to the second embodimentserves as a detector that detects force based on the difference betweenthe following outputs: the output (touch detection signals Vdet) intouch detection based on the capacitance of the touch detectionelectrode (touch detection electrode TDL) with which the strain gauge(e.g., the force detector 71 or 72) is integrated, and the output intouch detection based on the capacitance of the touch detectionelectrode at which the strain gauge is not provided.

As described above, the display apparatus with a touch detectionfunction 1 of the second embodiment can detect force based on thedifference between the output (touch detection signals Vdet) in touchdetection based on the capacitance of the touch detection electrode(touch detection electrode TDL) with which the strain gauge (e.g., theforce detector 71 or 72) is integrated and the output in touch detectionbased on the capacitance of the touch detection electrode at which thestrain gauge is not provided. The display apparatus with a touchdetection function 1 of the second embodiment thus can perform forcedetection simultaneously with touch detection. As a result, the displayapparatus with a touch detection function 1 of the second embodiment hasno need to supply voltage for force detection to the strain gauge at atiming different from the timing of touch detection or no restrictionson the timings. Consequently, the second embodiment does not require theconstant voltage circuit 15, for example.

In the same manner as the second embodiment, the first embodiment canalso perform touch detection based on the capacitance. In this case,however, the touch detector 40 needs to store therein in advanceinformation serving as a reference of a case where no force is applied.

First Modification: Modification of the Second Embodiment

The following describes a modification (first modification) of thesecond embodiment with reference to FIGS. 25 to 27. In the descriptionof the first modification, components similar to those of the secondembodiment are denoted by the same reference numerals, and explanationthereof may be omitted.

FIG. 25 is a diagram schematically illustrating an exemplaryconfiguration that operates the two systems in parallel. The secondembodiment described with reference to FIG. 20 employs the method ofswitching the two systems by the switch SW1. Alternatively, the twosystems may be coupled to corresponding dedicated ADCs 43 as illustratedin FIG. 25.

FIG. 26 is a diagram schematically illustrating an example of outputsfrom the two systems obtained when no force is applied according to thefirst modification. FIG. 27 is a diagram schematically illustrating anexample of difference between outputs from the two systems obtained whenforce is applied according to the first modification. The touchdetection electrodes TDL according to the first modification are thesame as those of the embodiment. Because each of the two systemsaccording to the first modification uses a corresponding one of thededicated ADCs 43, touch detections of the two systems can be performedat the same time in parallel. As illustrated in FIG. 26, if the outputpattern (RX2 t 1) of the touch detection signal Vdet that is output fromthe second system RX2 from the start timing to the end timing of touchdetection is substantially identical with the output pattern (RX1 t 1)of the touch detection signal Vdet that is output from the first systemRX1 from the start timing to the end timing of touch detection, it isdetermined that no force is applied by a touch operation. By contrast,when force is applied by a touch operation, difference is detectedbetween the output pattern (RX2 t 1) of the touch detection signal Vdetthat is output from the second system RX2 from the start timing to theend timing of touch detection and the output pattern (RX1 t 1) of thetouch detection signal Vdet that is output from the first system RX1from the start timing to the end timing of touch detection asillustrated in FIG. 27.

The first modification does not require the switch SW1 according to thesecond embodiment or need not perform switching control on the switchSW1. The first modification can receive outputs (touch detection signalsVdet) from the two systems simultaneously, and perform force detectionmore accurately.

Third Embodiment

The following describes an embodiment (third embodiment) part of theconfiguration of which is different from those of the first and thesecond embodiments with reference to FIGS. 28 to 30. In the descriptionof the third embodiment, components similar to those of the first andthe second embodiments are denoted by the same reference numerals, andexplanation thereof may be omitted.

FIG. 28 is a schematic wiring diagram of exemplary arrangement of theforce detectors 71 and 72 according to the third embodiment. FIG. 29 isa diagram of an example of a configuration of the force detector 71 anda portion near the force detector 71 according to the third embodiment.FIG. 30 is a diagram of an example of a specific configuration of theforce detector 72 and a portion near the force detector 72 according tothe third embodiment. The arrangement of the force detectors 71 and 72according to the second embodiment is the same as that of the forcedetectors 71 and 72 according to the first embodiment described withreference to FIG. 9. In other words, between each touch detectionelectrode TDL and the wiring, a corresponding one of the force detectors71 and 72 is provided according to the second embodiment. Alternatively,some of the touch detection electrodes TDL may not be provided with theforce detectors 71 and 72. As illustrated in FIG. 28, for example, afirst line and a second line may be alternately arranged in theextending direction of the drive electrodes COML. The first line isprovided with one of the force detectors 71 and 72 between the touchdetection electrode TDL and the wiring. The second line is not providedwith the force detector 71 and the force detector 72 between the touchdetection electrode TDL and the wiring. In this case, as illustrated inFIGS. 29 and 30, one first line and one second line adjacent to eachother are considered to be a pair. The first line is considered to bethe first system RX1, whereas the second line is considered to be thesecond system RX2. With this configuration, in the third embodiment,touch detection and force detection can be performed in parallel basedon the touch detection signals Vdet in the same manner as that of thesecond embodiment. The interval between the touch detection electrodesTDL of the first line and the second line according to the thirdembodiment is larger than the interval between the touch detectionelectrodes TDL of the first system RX1 and the second system RX2according to the second embodiment. Thus, the display apparatus with atouch detection function 1 of the third embodiment preferably correctsthe output considering the interval in force detection or performsadjustment such that the intervals are the same in terms of wiringresistance.

As described above, the third embodiment employs the arrangement of theforce detectors 71 and 72 illustrated in FIG. 28. In this case, thethird embodiment may employ a force detection method similar to thataccording to the first embodiment, that is, a method for detecting forceby supplying voltage to the touch detection electrodes TDL provided withthe force detectors 71 and 72 and measuring the electrical resistancevalue.

As described above, the third embodiment can provide advantageouseffects as those of the first and the second embodiments.

Fourth Embodiment

The following describes an embodiment (fourth embodiment) part of theconfiguration of which is different from those of the first to the thirdembodiments with reference to FIGS. 31 to 35. In the description of thefourth embodiment, components similar to those of the first to the thirdembodiments are denoted by the same reference numerals, and explanationthereof may be omitted.

FIG. 31 is a schematic wiring diagram of the relation between the forcedetectors 71 and 72 and the touch detection electrodes TDL according tothe fourth embodiment. FIG. 32 is a diagram of an example of aconfiguration of the force detector 71 and a portion near the forcedetector 71 according to the fourth embodiment. FIG. 33 is a diagram ofan example of a specific configuration of the force detector 72 and aportion near the force detector 72 according to the fourth embodiment.As illustrated in FIGS. 31 to 33, the wiring that couples the touchdetection electrode TDL to the touch detector 40 may have two systems,and a first system RX1 out of the two systems may include the forcedetectors 71 and 72. In this case, the first system RX1 out of the twosystems of the wiring can be considered to be the first system RX1according to the second embodiment, whereas a second system RX2 out ofthe two systems of the wiring can be considered to be the second systemRX2 according to the second embodiment. The various methods fordetecting force described with reference to FIGS. 12 to 17 are alsoapplicable to the fourth embodiment. Specifically, by considering thefirst system RX1 to be the coupling line Q, for example, the variousmethods for detecting force can be applied to the fourth embodiment.

FIGS. 34 and 35 are diagrams schematically illustrating an exemplaryconfiguration that selectively operates the two systems according to thefourth embodiment. FIG. 34 illustrates a coupling state in touchdetection. FIG. 35 illustrates a coupling state in force detection. Asillustrated in FIGS. 34 and 35, for example, the fourth embodimentincludes a switch SW2 on a coupling path that couples the second systemRX2 to the ADC 43 or a resistance change detection circuit 47. Theswitch SW2 can switch between a first mode in which the second systemRX2 is coupled to the ADC 43 and a second mode in which the secondsystem RX2 is coupled to the resistance change detection circuit 47. Asillustrated in FIGS. 34 and 35, for example, the fourth embodimentfurther includes a switch SW3 on a coupling path that couples the firstsystem RX1 to the resistance change detection circuit 47. The switch SW3can switch between a coupling mode in which the first system RX1 iscoupled to the resistance change detection circuit 47 and a decouplingmode in which the first system RX1 is decoupled from the resistancechange detection circuit 47. The resistance change detection circuit 47uses the second system RX2 as standards (reference). The resistancechange detection circuit 47 detects a change in the electricalresistance in the first system RX1 that increases depending on forceapplied by a touch operation, thereby performing force detection. Inother words, if the difference in the electrical resistance between thefirst system RX1 and the second system RX2 is 0 or equivalent to 0, itis determined that no force is applied by a touch operation as a resultof force detection. By contrast, if the difference in the electricalresistance between the first system RX1 and the second system RX2 issignificantly larger than 0, it is determined that force correspondingto the magnitude of the difference is applied by a touch operation as aresult of force detection. As illustrated in FIG. 34, in the fourthembodiment, the second system RX2 is coupled to the ADC 43 in touchdetection. Also, in the fourth embodiment, both the first system RX1 andthe second system RX2 are coupled to the resistance change detectioncircuit 47 in force detection.

As described above, the touch detection electrodes TDL according to thefourth embodiment each include the two systems. This configuration canprovide the touch detection signals Vdet not passing through the forcedetector 71 or 72 without increasing the number of touch detectionelectrodes TDL. In other words, according to the fourth embodiment, theoutput of the touch detection signals Vdet can be easily increased andthe power consumption in outputting the touch detection signals Vdet isreduced.

Second Modification

The following describes a modification (second modification) of thefirst to the fourth embodiments with reference to FIG. 36. In thedescription of the second modification, components similar to those ofthe first to the fourth embodiments are denoted by the same referencenumerals, and explanation thereof may be omitted.

FIG. 36 is a diagram of an example of a specific configuration of theforce detector 72 and a portion near the force detector 72 according tothe second modification. As illustrated in FIG. 36, the touch detectionelectrodes TDL may have a mesh structure. While the touch detectionelectrodes TDL illustrated in FIG. 36 have a rhombic mesh structure, theshape of the mesh is not particularly restricted and may beappropriately changed. As described above, the mesh structure of theelectrodes in the display area 20 a, such as the touch detectionelectrodes TDL, can make the touch detection electrodes TDL less likelyto be visually recognized, thereby reducing a visual influence of thetouch detection electrodes TDL on display output.

As illustrated in FIG. 36, the path of the electrode lines of the straindetection patterns and the folded patterns in the force detector 72 mayhave the same mesh structure as that of the touch detection electrodesTDL. The sides of the mesh structure may be uncoupled at positionscorresponding to the gaps between a plurality of strain detectionpatterns. This structure can make the strain detection patternselectrically uncoupled in the intersection direction. As a result, theforce detector 72 described with reference to FIG. 11 can have a meshstructure. While the folded patterns are not thicker than the straindetection patterns in the mesh structure illustrated in FIG. 36, thestrain detection patterns simply need to have a sufficient length in thedetection direction. As described above, the force detectors 72 have thesame mesh structure as that of the electrodes in the display area 20 a,such as the touch detection electrodes TDL. This structure can reduce avisual influence caused in a case where the force detectors 72 arearranged in the display area 20 a. In other words, while the forcedetectors 72 are arranged outside the display area 20 a according to thefirst to the fourth embodiments, the force detectors 72 can be easilyarranged inside the display area 20 a according to the secondmodification.

As illustrated in FIG. 36, dummy electrodes DD may be arranged aroundthe touch detection electrodes TDL and the force detectors 72. The dummyelectrodes DD have a mesh structure (e.g., a rhombic shape) the sides ofwhich are cut off. With the dummy electrodes DD, the configurationsarranged according to their functions, such as the touch detectionelectrodes TDL and the force detectors 72, can be provided as part of awider mesh structure including the dummy electrodes DD. In other words,the dummy electrodes DD can widen the mesh structure in the display area20 a, thereby making the mesh structure less likely to be visuallyrecognized compared with a case where the mesh structure is locallyprovided.

While the force detector 72 having a mesh structure is illustrated inFIG. 36, the same mesh structure may also be applied to the forcedetector 71. The above mentioned electrodes having a mesh structure andthe dummy electrodes DD may be made of metal.

As described above, the second modification facilitates arrangement ofthe strain gauges (force detectors 71 and 72) in the display area 20 a.Consequently, the second modification can make the frame area thinner.

Fifth Embodiment

The following describes an embodiment (fifth embodiment) part of theconfiguration of which is different from those of the first to thefourth embodiments with reference to FIGS. 37 to 43. In the descriptionof the fifth embodiment, components similar to those of the first to thefourth embodiments are denoted by the same reference numerals, andexplanation thereof may be omitted.

FIG. 37 is a diagram of an example of a module 1A provided with thedisplay apparatus with a touch detection function according to the fifthembodiment. The module 1A of the fifth embodiment includes touchdetection electrodes 80 instead of the touch detection electrodes TDL.The touch detection electrodes 80 are self-capacitive electrodes havingcapacitance that changes depending on a touch operation performed on thetouch detection surface. Specifically, as illustrated in FIG. 37, forexample, the touch detection electrodes 80 are arranged in atwo-dimensional matrix in the display area 20 a. The touch detectionelectrodes 80 are electrically coupled to the drive electrode driver 14and the printed circuit board PB via wiring provided using a wiringlayer. The touch detection electrodes 80 each transmit an outputindicating self-capacitance to the printed circuit board PB at a drivetiming of the drive electrode driver 14. Because the self-capacitancechanges depending on a touch operation performed on the display area 20a, touch detection can be performed based on the outputs from the touchdetection electrodes 80.

The following describes a basic principle of self-capacitive touchdetection with reference to FIGS. 38 to 40.

FIG. 38 is a diagram for explaining the basic principle ofself-capacitive touch detection and illustrates a state where a fingerFi is neither in contact with nor in proximity to a touch detectionelectrode. FIG. 39 is a diagram for explaining the basic principle ofself-capacitive touch detection and illustrates a state where the fingerFi is in contact with or in proximity to the touch detection electrode.FIG. 40 is a diagram of an example of waveforms of a drive signal and atouch detection signal.

As illustrated in FIG. 38, in a state where the finger Fi is neither incontact with nor in proximity to the touch detection electrode, an ACrectangular wave Sg1 having a predetermined frequency (e.g., frequencyon the order of several kilohertz to several hundred kilohertz) isapplied to a touch detection electrode E3. The touch detection electrodeE3 has capacitance C1, and an electric current corresponding to thecapacitance C1 flows. A voltage detector DETa converts the change in theelectric current in relation to the AC rectangular wave Sg1 into changein voltage (waveform V₄ indicated by the solid line (refer to FIG. 40)).

As illustrated in FIG. 39, in a state where the finger Fi is in contactwith or in proximity to the touch detection electrode, capacitance C2between the finger Fi and the touch detection electrode E3 is added tothe capacitance C1 of the touch detection electrode E3. When the ACrectangular wave Sg1 is applied to the touch detection electrode E3, anelectric current corresponding to the capacitance C1 and C2 flows. Asillustrated in FIG. 40, the voltage detector DETa converts change in theelectric current in relation to the AC rectangular wave Sg1 into changein voltage (waveform V₅ indicated by the dotted line). By integratingthe voltage values of the waveforms V₄ and V₅ and comparing thesevalues, it is determined whether the finger Fi is in contact with or inproximity to the touch detection electrode E3. Alternatively, anothermethod may be employed, such as a method of calculating respectiveperiods required for a waveform V₂ and a waveform V₃ illustrated in FIG.40 to decrease to predetermined reference voltage and comparing theperiods.

Specifically, as illustrated in FIGS. 38 and 39, the touch detectionelectrode E3 can be cut off by a switch SWa and a switch SWb. In FIG.40, the voltage level of the AC rectangular wave Sg1 raises by an amountcorresponding to voltage V₆ at time T₀₁. At this time, the switch SWa isturned on, and the switch SWb is turned off. As a result, the voltage inthe touch detection electrode E3 is also raised by V₆. When the switchSWa is turned off, the touch detection electrode E3 gets into a floatingstate. At this time, the voltage in the touch detection electrode E3 ismaintained at V₆ by the capacitance C1 (refer to FIG. 38) of the touchdetection electrode or capacitance (C1+C2, refer to FIG. 39) obtained byadding the capacitance C2 generated by contact or proximity of thefinger Fi or the like to the capacitance C1 of the touch detectionelectrode. Subsequently, a switch SW3 is turned on before time T₁₁ andis turned off after a predetermined time has elapsed, thereby resettingthe voltage detector DETa. With this reset operation, the output voltageis made substantially equal to reference voltage Vref.

Subsequently, when the switch SWb is turned on at time T₁₁, the voltagein an inversion input end of the voltage detector DETa increases to thevoltage V₆ equal to that of the touch detection electrode E3.Subsequently, the voltage in the inversion input end of the voltagedetector DETa decreases to the reference voltage Vref based on a timeconstant of the capacitance C1 (or C1+C2) of the touch detectionelectrode E3 and the capacitance C3 in the voltage detector DETa. Atthis time, the electric charges accumulated in the capacitance C1 (orC1+C2) of the touch detection electrode E3 move to the capacitance C3 inthe voltage detector DETa, whereby an output (VdetA) from the voltagedetector DETa increases. When the finger Fi or the like is not inproximity to the touch detection electrode E3, the output (VdetA) fromthe voltage detector DETa is represented by the waveform V₄ indicated bythe solid line, and R1=C1·V₆/C3 is satisfied. When capacitance generatedby an effect of the finger Fi or the like is added, the output isrepresented by the waveform V₅ indicated by the dotted line, andVdetA=(C1+C2)·V₆/C3 is satisfied. Subsequently, at time T₃₁ after theelectric charges in the capacitance C1 (or C1+C2) of the touch detectionelectrode E3 sufficiently move to the capacitance C3, the switch SWb isturned off, and the switch SWa and the switch SW3 are turned on. As aresult, the electric potential of the touch detection electrode E3decreases to a low level equal to that of the AC rectangular wave Sg1,and the voltage detector DETa is reset. The timing to turn on the switchSWa may be any timing as long as it is after the turning off of theswitch SWb and before time T₀₂. The timing to reset the voltage detectorDETa may be any timing as long as it is after the turning off of theswitch SWb and before time T₁₂. The operation described above isrepeatedly performed at a predetermined frequency (e.g., frequency onthe order of several kilohertz to several hundred kilohertz). The touchdetector 40 can determine whether an external proximate object ispresent (whether a touch operation is performed) based on the absolutevalue |ΔV| of the difference between the waveform V₄ and the waveformV₅. As illustrated in FIG. 40, when the finger Fi or the like is not inproximity to the touch detection electrode, the electric potential ofthe touch detection electrode E3 is represented by the waveform V₂. Bycontrast, when the capacitance C2 generated by an effect of the fingerFi or the like is added, the electric potential is represented by thewaveform V₃. By measuring a time required for the waveforms V₂ and V₃ todecrease to predetermined voltage V_(TH), the touch detector 40 maydetermine whether an external proximate object is present (whether atouch operation is performed).

The various methods for detecting force described with reference toFIGS. 12 to 17 are also applicable to the fifth embodiment.Specifically, for example, the coupling end U is provided at one of thewiring between the drive electrode driver 14 illustrated in FIG. 37 andthe touch detection electrodes 80 and the wiring between the touchdetection electrodes 80 and the printed circuit board PB, and thecoupling line Q is coupled to the other thereof. With thisconfiguration, the various methods for detecting force can be applied tothe fifth embodiment.

The touch detection electrodes 80 have a structure to detect force.Specifically, the touch detection electrodes 80 arranged in atwo-dimensional matrix include touch detection electrodes 81 and touchdetection electrodes 82 (FIGS. 41 to 43). Each of the touch detectionelectrodes 81 is provided with the touch detector 71, whereas each ofthe touch detection electrodes 82 is provided with the touch detector72.

FIG. 41 is a diagram of exemplary arrangement of the touch detectionelectrodes 81 and 82. As illustrated in FIG. 41, the touch detectionelectrodes 81 and 82 are alternately arranged in the row and columndirections.

FIG. 42 is a diagram of an example of a specific configuration of theforce detector 71 and a portion near the force detector 71 according tothe fifth embodiment. FIG. 43 is a diagram of an example of a specificconfiguration of the force detector 72 and a portion near the forcedetector 72 according to the fifth embodiment. FIGS. 42 and 43 do notillustrate the wiring that couples the touch detection electrodes 81 and82 to the drive electrode driver 14. As illustrated in FIG. 42, forexample, the touch detection electrode 81 with the force detector 71includes a self-capacitance forming electrode 81 a serving as anelectrode having rectangular four sides surrounding the force detector71. As illustrated in FIG. 43, for example, the touch detectionelectrode 82 with the force detector 72 includes a self-capacitanceforming electrode 82 a serving as an electrode having rectangular foursides surrounding the force detector 72. The shape of theself-capacitance forming electrodes 81 a and 82 a may be appropriatelychanged.

In the fifth embodiment, switching operations are performed in touchdetection and in force detection in the same manner as that of thefourth embodiment described with reference to FIGS. 34 and 35. Theconfiguration of the touch detector 40 on the downstream side of the ADC43 according to the fifth embodiment is a configuration on which analgorithm for performing self-capacitive detection is implemented. Oneof the four sides of the self-capacitance forming electrodes 81 a and 82a has a cut-out through which the wiring of the first system RX1 coupledto the force detector 71 passes, and the wiring is coupled to the switchSW3. The force detector 71 and the self-capacitance forming electrode 81a share the wiring of the second system RX2, and the wiring is coupledto the switch SW2. The same can be applied to the coupling relationbetween the self-capacitance forming electrode 82 a and wiring.

As described above, according to the fifth embodiment, the strain gauges(force detectors 71 and 72) can be arranged in a matrix in the displayarea 20 a.

Sixth Embodiment

The following describes an embodiment (sixth embodiment) part of theconfiguration of which is different from those of the first to the fifthembodiments with reference to FIGS. 44 to 50. In the description of thesixth embodiment, components similar to those of the first to the fifthembodiments are denoted by the same reference numerals, and explanationthereof may be omitted.

FIG. 44 is a schematic wiring diagram of exemplary arrangement of forcedetectors 91, 92, 93, and 94 according to the sixth embodiment. Each ofthe force detectors 91, 92, 93, and 94 according to the sixth embodimentis integrated with a corresponding one of the drive electrodes COML. Thevarious methods for detecting force described with reference to FIGS. 12to 17 are also applicable to the sixth embodiment. Specifically, thecoupling end U is provided on the force detectors 91, 92, 93, and 94side of the drive electrodes COML, and the coupling line Q is providedon the side opposite thereto. With this configuration, the variousmethods for detecting force can be applied to the sixth embodiment.

FIG. 45 is a diagram of an example of a specific configuration of theforce detector 91 and a portion near the force detector 91. FIG. 46 is adiagram of an example of a specific configuration of the force detector92 and a portion near the force detector 92. The force detector 91 hasstrain detection patterns 91 a and folded patterns 91 b having the samedetection direction and the same intersection direction as those of theforce detector 71. The force detector 92 has strain detection patterns92 a and folded patterns 92 b having the same detection direction andthe same intersection direction as those of the force detector 71. Eachof the drive electrodes COML has one end and the other end opposite tothe one end. As illustrated in FIGS. 44 and 45, each of the forcedetectors 91 is provided as a component connected to a corresponding oneof the drive electrodes COML at the one end thereof. As illustrated inFIGS. 44 and 46, each of the force detectors 92 is provided as acomponent connected to a corresponding one of the drive electrodes COMLat the other end thereof. More specifically, a side of the frame areaprovided with the force detectors 91 is opposite to a side of the framearea provided with the force detectors 92 with the display area 20 asandwiched therebetween.

FIG. 47 is a diagram of an example of a specific configuration of theforce detector 93 and a portion near the force detector 93. FIG. 48 is adiagram of an example of a specific configuration of the force detector94 and a portion near the force detector 94. The force detector 93 hasstrain detection patterns 93 a and folded patterns 93 b having the samedetection direction and the same intersection direction as those of theforce detector 72. The force detector 94 has strain detection patterns94 a and folded patterns 94 b having the same detection direction andthe same intersection direction as those of the force detector 72. Asillustrated in FIGS. 44 and 47, each of the force detectors 93 isprovided as a component connected to a corresponding one of the driveelectrodes COML at the one end thereof. As illustrated in FIGS. 44 and48, each of the force detectors 94 is provided as a component connectedto a corresponding one of the drive electrodes COML at the other endthereof. More specifically, a side of the frame area provided with theforce detectors 93 is opposite to a side of the frame area provided withthe force detectors 94 with the display area 20 a sandwichedtherebetween.

The force detectors 91, 92, 93, and 94 according to the sixth embodimentdetect force with the same mechanism as that of the first embodiment. Inother words, the drive electrodes COML according to the sixth embodimentare supplied with voltage for force detection at the timing of forcedetection. The voltage may be supplied by the drive electrode driver 14or another component, such as the constant voltage circuit 15. Outputlines of the force detectors 91, 92, 93, and 94 output signalsindicating the electrical resistance in the force detectors 91, 92, 93,and 94, respectively, according to the supply of voltage. The outputlines may be provided in the same layer as that of the drive electrodesCOML or another layer.

FIG. 49 is a timing chart schematically illustrating an example of therelation between touch detection timings and force detection timingsaccording to the sixth embodiment. In FIG. 49, to distinguish theoperation timings of three different drive electrodes COML, the timingcharts of the respective drive electrodes COML are denoted by TX1, TX2,and TX3. The waveforms of the timing charts illustrated in FIG. 49 donot indicate the height or the like of voltage of signals but simplyindicate the timings. As illustrated in FIG. 49, for example, a timing(time slot) to supply the drive electrode COML with the drive signalVcom for forming capacitance with the touch detection electrodes TDL intouch detection is different from a timing (time slot) to supply thedrive electrode COML with voltage for performing force detection, theforce detection according to the sixth embodiment being performed usingthe force detectors 91, 92, 93, and 94. While the timing chartsillustrated in FIG. 49 have timings (time slots) when neither touchdetection nor force detection is performed in terms of an operation ofone drive electrode COML, one of touch detection and force detection maybe performed at the timings (in the time slots). While FIG. 49illustrates the timing charts of three drive electrodes COML, the fourthdrive electrode COML and those subsequent thereto also operate atdifferent timings similarly to the relation between the three driveelectrodes COML illustrated in FIG. 49.

FIG. 50 is a schematic waveform diagram of an example of the relationbetween a synthesized signal for forming capacitance between the touchdetection electrode TDL and the drive electrode COML, the drive signalVcom for touch detection, and a drive signal (supply of voltage) forforce detection. According to the sixth embodiment, for example, at atiming when part of the drive electrodes COML are supplied with thedrive signal Vcom for touch detection, other part thereof may possiblybe supplied with voltage for force detection, as illustrated in FIGS. 49and 50. In terms of the touch detection electrodes TDL, as illustratedin FIG. 50, signals each of which is obtained by synthesizing the drivesignal Vcom with the voltage for force detection are supplied from thedrive electrodes COML. The potential difference caused by an increase involtage in association with supply of the voltage used for forcedetection is significantly smaller than the potential difference in therise and fall patterns of the voltage indicated by the drive signal Vcomused for touch detection. As a result, as illustrated in FIG. 50, thepotential difference in the rise and fall patterns of the voltage causedby the drive signal Vcom used for touch detection is large enough to berecognized in the synthesized signals. In the sixth embodiment, thesynthesized signals is corrected considering the potential difference(D1) caused by supply of the voltage for force detection. The correctionis performed by the signal processor 44, for example. Alternatively, thecorrection may be performed by a dedicated component.

The sixth embodiment is applicable to both mutual capacitive andself-capacitive display apparatuses with a touch detection function. Ina case where the sixth embodiment is applied to a display apparatus, thedisplay apparatus does not require the force detector 71 or 72 accordingto the first to the fifth embodiments. The sixth embodiment can beapplied to any configuration as long as it includes the drive electrodesCOML. The sixth embodiment may be applied to a display apparatus havingno touch detection function. In this case, the display apparatus doesnot require components that detect a touch operation, such as the touchdetection electrodes TDL. As described above, the display apparatusaccording to the sixth embodiment includes the strain gauge integratedwith the drive electrode used to drive the pixels. The strain gauge isany one of the force detectors 91, 92, 93, and 94, for example.

As described above, according to the sixth embodiment, the strain gauge(e.g., the force detectors 91, 92, 93, and 94) is integrated with thedrive electrode used to drive the pixels. As a result, the configurationthat performs display can be integrated with the configuration thatperforms force detection. Thus, force can be detected by a configurationintegrated with a component used for another configuration(configuration that performs display).

Third Modification

The following describes a modification (third modification) of the sixthembodiment with reference to FIGS. 51 to 55. In the description of thethird modification, components similar to those of the sixth embodimentare denoted by the same reference numerals, and explanation thereof maybe omitted.

FIG. 51 is a schematic wiring diagram of exemplary arrangement of forcedetectors 91A, 92A, 93A, and 94A according to the third modification.FIG. 52 is a diagram of an example of a specific configuration of theforce detector 91A and a portion near the force detector 91A. FIG. 53 isa diagram of an example of a specific configuration of the forcedetector 92A and a portion near the force detector 92A. FIG. 54 is adiagram of an example of a specific configuration of the force detector93A and a portion near the force detector 93A. FIG. 55 is a diagram ofan example of a specific configuration of the force detector 94A and aportion near the force detector 94A. The force detector 91A has straindetection patterns 91Aa and folded patterns 91Ab. The force detector 92Ahas strain detection patterns 92Aa and folded patterns 92Ab. The forcedetector 93A has strain detection patterns 93Aa and folded patterns93Ab. The force detector 94A has strain detection patterns 94Aa andfolded patterns 94Ab. In the FIGS. 52 to 55, some reference numerals ofthe strain detection patterns 91Aa to 94Aa and folded patterns 91Ab to94Ab are omitted. The arrangement of the force detectors 91A, 92A, 93A,and 94A according to the third modification is the same as that of theforce detectors 91, 92, 93, and 94 according to the sixth embodiment. Inthe sixth embodiment, the output lines of the force detectors 91, 92,93, and 94 that respectively output signals indicating the electricalresistance of the force detectors 91, 92, 93, and 94 according to thesupply of voltage are wiring different from the drive electrodes COML.By contrast, in the third modification, the output lines of the forcedetectors 91A, 92A, 93A, and 94A also serve as the drive electrodes COMLas illustrated in FIGS. 52 to 55.

Specifically, as illustrated in FIG. 51, for example, a displayapparatus with a touch detection function of the third modificationincludes the drive electrode driver 14 and a relay 14 a. The driveelectrode driver 14 is provided at one ends of the drive electrodesCOML, and the relay 14 a is provided at the other ends of the driveelectrodes COML. The drive electrode driver 14 and the relay 14 a faceeach other with the display area 20 a sandwiched therebetween. The relay14 a applies the drive signal Vcom received from the drive electrodedriver 14 to the drive electrode COML from the end of the driveelectrode COML positioned opposite to the drive electrode driver 14 withthe display area 20 a sandwiched therebetween. The relay 14 a, forexample, is coupled to wiring that transmits the drive signal Vcomreceived from the drive electrode driver 14 to the end of the driveelectrode COML positioned opposite to the drive electrode driver 14 withthe display area 20 a sandwiched therebetween. The relay 14 a may be adrive electrode driver provided separately from the drive electrodedriver 14. The various methods for detecting force described withreference to FIGS. 12 to 17 are also applicable to the thirdmodification similarly to the sixth embodiment.

The drive signal Vcom according to the third modification passes throughthe force detector integrated with the drive electrode COML and reachesthe drive electrode COML in the display area 20 a. The force detectorintegrated with the drive electrode COML is one of the force detectors91A, 92A, 93A, and 94A. Specifically, the force detectors 91A and 93Aprovided on the relay 14 a side and the drive electrodes COML integratedtherewith are supplied with the drive signal Vcom from the relay 14 a.By contrast, the force detectors 92A and 94A provided on the driveelectrode driver 14 side and the drive electrodes COML integratedtherewith are supplied with the drive signal Vcom from the driveelectrode driver 14.

As described above, according to the third modification, the electricalsystems of the respective drive electrodes COML are integrated into onesystem.

Fourth Modification

The following describes a modification (fourth modification) of thesixth embodiment with reference to FIG. 56. In the description of thefourth modification, components similar to those of the sixth embodimentare denoted by the same reference numerals, and explanation thereof maybe omitted.

FIG. 56 is a timing chart schematically illustrating an example of therelation between drive timings of the drive electrodes COML and touchdetection timings of the touch detection electrodes TDL in touchdetection according to the fourth modification. In FIG. 56, todistinguish the touch detection timings of three different touchdetection electrodes TDL, timing charts of the respective touchdetection electrodes TDL are denoted by RXa, RXb, and RXc. In the sixthembodiment, touch detection and force detection can be performed inparallel using the touch detection signals Vdet in capacitive touchdetection. Specifically, as illustrated in FIG. 56, for example, whenthe drive signal Vcom is supplied to one of the drive electrodes COML intouch detection, the touch detection signals Vdet are output from thetouch detection electrodes TDL at a timing later than the supply timingof the drive electrode COML. If force is applied by a touch operation,the electrical resistance in the drive electrodes provided with theforce detectors (e.g., the force detectors 91, 92, 93, and 94) increasescompared with a case where no force is applied. In other words, if forceis applied by a touch operation, the gap between the supply timing ofthe drive electrode COML and the output timing of the touch detectionsignals Vdet in touch detection increases compared with a case where noforce is applied. As illustrated in FIG. 56, for example, the gapbetween a supply timing S3 of the drive electrode COML and an outputtiming R3 of the touch detection signals Vdet obtained when force isapplied by a touch operation is larger than the gaps between supplytimings S1 and S2 of the drive electrode COML and output timings R1 andR2 of the touch detection signals Vdet, respectively, obtained when noforce is applied.

The processing for detecting force described with reference to FIG. 56is performed by the signal processor 44, for example. In other words,the touch detector 40 according to the fourth modification serves as adetector that detects force based on the output timing of the drivesignal for forming an electric field and the output timing of touchdetection signal from the touch detection electrodes. In a similarmanner to the first embodiment and other embodiments, the driveelectrodes according to the fourth modification that performs forcedetection are not in contact with the touch detection electrodes to forman electric field between the touch detection electrodes and the driveelectrodes according to the drive signal.

As described above, according to the fourth modification, forcedetection can be performed simultaneously with touch detection. As aresult, there is no need to supply voltage for force detection to thestrain gauge (e.g., the force detectors 91A, 92A, 93A, and 94A) at atiming different from the timing of touch detection or no need forrestrictions on the timings. Consequently, the fourth modification doesnot require the constant voltage circuit 15, for example.

While the first to the sixth embodiments and the first to the fourthmodifications have been described, the configuration of the presentinvention may be appropriately changed within the range specified by theinvention specification items described in the claims. The firstembodiment and the other embodiments and modifications, for example,employ what is called an in-cell apparatus in which the drive electrodesCOML are shared by the configuration that performs touch detection andthe configuration that performs display output. Alternatively, thedisplay apparatus with a touch detection may be applied to what iscalled an on-cell apparatus in which the drive electrodes COML are notshared.

In a case where a display apparatus with a touch detection is an on-cellapparatus or an out-cell apparatus, the drive electrodes COML used forat least one of touch detection and force detection according to thefirst embodiment and the other embodiments and modifications areprovided as components different from the drive electrodes COML providedin the first substrate 2. Whether to provide a display device isoptionally determined. In other words, the detecting apparatus mayinclude only the touch detecting device 30 according to the firstembodiment and the other embodiments and modifications and theconfiguration relating to the operations of the touch detecting device30, for example. In a case where a display device is provided, theconfiguration of the display device may be optionally determined. Thedisplay device may be a display device other than liquid crystal displaydevices, such as an organic EL display device.

FIG. 57 is a diagram of an example of a sectional structure of anorganic EL display device. The image display panel includes pixels 48arranged in a two-dimensional matrix in the row direction and the columndirection and displays an image of each display frame.

The pixels 48 each include a plurality of sub-pixels 49. A lightingdrive circuit includes a control transistor, a drive transistor, and acharge retention capacitor. The gate of the control transistor iscoupled to a scanning line, the source thereof is coupled to a signalline, and the drain thereof is coupled to the gate of the drivetransistor. A first end of the charge retention capacitor is coupled tothe gate of the drive transistor, and a second end thereof is coupled tothe source of the drive transistor. The source of the drive transistoris coupled to a power supply line, and the drain thereof is coupled tothe anode of an organic light-emitting diode serving as a light emitter.The cathode of the organic light-emitting diode is coupled to areference potential (e.g., the ground), for example. The controltransistor is an re-channel transistor, and the drive transistor is ap-channel transistor, for example. The polarities of the respectivetransistors are not limited thereto. The polarities of the controltransistor and the drive transistor may be determined as needed.

The pixels 48 each include a first sub-pixel 49R, a second sub-pixel49G, a third sub-pixel 49B, and a fourth sub-pixel 49W, for example. Thefirst sub-pixel 49R, the second sub-pixel 49G, the third sub-pixel 49B,and the fourth sub-pixel 49W are arrayed in a stripe pattern in onedirection, for example. The first sub-pixel 49R displays a primary colorof red serving as a first color. The second sub-pixel 49G displays aprimary color of green serving as a second color. The third sub-pixel49B displays a primary color of blue serving as a third color. Thefourth sub-pixel 49W displays white serving as a fourth color differentfrom the first, the second, and the third colors. The first color, thesecond color, the third color, and the fourth color are not limited tored, green, blue, and white, respectively, and may be desired colors,such as complimentary colors.

As illustrated in FIG. 57, the image display panel includes a substrate51, insulation layers 52 and 53, a reflective layer 54, lower electrodes55, a light-emitting layer 56, upper electrodes 57, an insulation layer58, an insulation layer 59, color filters 61 serving as a colorconversion layer, a black matrix 62 serving as a light-shielding layer,and a substrate 50. The substrate 51 is a semiconductor substrate madeof silicon, a glass substrate, or a resin substrate, for example, andincludes or holds the lighting drive circuit. The insulation layer 52 isa protective film that protects the lighting drive circuit and is madeof silicon oxide or silicon nitride, for example. The first sub-pixel49R, the second sub-pixel 49G, the third sub-pixel 49B, and the fourthsub-pixel 49W each are provided with the lower electrode 55. The lowerelectrode 55 is a conductor serving as the anode (positive electrode) ofthe organic light-emitting diode. The lower electrode 55 is atranslucent electrode made of a translucent conductive material(translucent conductive oxide), such as indium tin oxide (ITO). Theinsulation layer 53 is called a bank and separates the first sub-pixel49R, the second sub-pixel 49G, the third sub-pixel 49B, and the fourthsub-pixel 49W from each other. The reflective layer 54 is made of amaterial having metallic luster, such as silver, aluminum, and gold,that reflects light from the light-emitting layer 56. The light-emittinglayer 56 is made of an organic material and includes a hole injectionlayer, a hole transport layer, a luminous layer, an electron transportlayer, and an electron injection layer, which are not illustrated.

Hole Transport Layer

A layer that generates a hole is preferably a layer including anaromatic amine compound and a substance having an electron-acceptingproperty for the compound, for example. The aromatic amine compound is asubstance having an arylamine skeleton. Among aromatic amine compounds,preferably used is an aromatic amine compound including triphenylaminein the skeleton and having a molecular weight of equal to or larger than400. Among aromatic amine compounds having triphenylamine in theskeleton, preferably used is an aromatic amine compound including acondensed aromatic ring, such as a naphthyl group, in the skeleton. Byusing the aromatic amine compound including triphenylamine and acondensed aromatic ring in the skeleton, the heat resistance of lightemitting elements can be improved. Examples of the aromatic aminecompound include, but are not limited to,4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: α-NPD),4,4′-bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (abbreviation: TPD),4,4′,4″-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine(abbreviation: MTDATA),4,4′-bis[N-{4-(N,N-di-m-tolylamino)phenyl}-N-phenylamino]biphenyl(abbreviation: DNTPD), 1,3,5-tris[N,N-di(m-tolyl)amino]benzene(abbreviation: m-MTDAB), 4,4′,4″-tris(N-carbazolyl)triphenylamine(abbreviation: TCTA), 2,3-bis(4-diphenylaminophenyl)quinoxaline(abbreviation: TPAQn),2,2′,3,3′-tetrakis(4-diphenylaminophenyl)-6,6′-bisquinoxaline(abbreviation: D-TriPhAQn),2,3-bis{4-[N-(1-naphthyl)-N-phenylamino]phenyl}-dibenzo[f,h]quinoxaline(abbreviation: NPADiBzQn), etc. The substance having anelectron-accepting property for the aromatic amine compound is notparticularly restricted. Examples of the substance include, but are notlimited to, molybdenum oxide, vanadium oxide,7,7,8,8-tetracyanoquinodimethane (abbreviation: TCNQ),2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (abbreviation:F4-TCNQ), etc.

Electron Injection Layer and Electron Transport Layer

An electron transport substance is not particularly restricted. Examplesof the electron transport substance include, but are not limited to, ametal complex, such as tris(8-quinolinolato)aluminum (abbreviation:Alq₃), tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq₃),bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviation: BeBq₂),bis(2-methyl-8-quinolinolato)-4-phenylphenolate-aluminum (abbreviation:BAlq), bis[2-(2-hydroxyphenyl)benzoxazolate]zinc (abbreviation:Zn(BOX)₂), and bis[2-(2-hydroxyphenyl)benzothiazolate]zinc(abbreviation: Zn(BTZ)₂),2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation:PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene(abbreviation: OXD-7),3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole(abbreviation: TAZ),3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole(abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen),bathocuproine (abbreviation: BCP), etc. A substance having anelectron-donating property for the electron transport substance is notparticularly restricted. Examples of the substance include, but are notlimited to, alkali metal such as lithium and cesium, alkaline-earthmetal such as magnesium and calcium, rare-earth metal such as erbium andytterbium, etc. A substance selected from alkali metal oxide andalkaline-earth metal oxide, such as lithium oxide (Li₂O), calcium oxide(CaO), sodium oxide (Na₂O), potassium oxide (K₂O), and magnesium oxide(MgO), may be used as a substance having an electron-donating propertyfor the electron transport substance.

Luminous Layer

To cause the luminous layer to emit red light, for example, a substancethat emits light having a peak of an emission spectrum of 600 nm to 680nm may be used. Examples of the substance include, but are not limitedto,4-dicyanomethylene-2-isopropyl-6-[2-(1,1,7,7-tetramethyljulolidine-9-yl)ethenyl]-4H-pyran(abbreviation: DCJTI),4-dicyanomethylene-2-methyl-6-[2-(1,1,7,7-tetramethyljulolidine-9-yl)ethenyl]-4H-pyran(abbreviation: DCJT),4-dicyanomethylene-2-tert-butyl-6-[2-(1,1,7,7-tetramethyljulolidine-9-yl)ethenyl]-4H-pyran(abbreviation: DCJTB), periflanthene,2,5-dicyano-1,4-bis[2-(10-methoxy-1,1,7,7-tetramethyljulolidine-9-yl)ethenyl]benzene,etc. To cause the luminous layer to emit green light, a substance thatemits light having a peak of an emission spectrum of 500 nm to 550 nmmay be used. Examples of the substance include, but are not limited to,N,N′-dimethylquinacridone (abbreviation: DMQd), coumalin 6, coumalin545T, tris(8-quinolinolato)aluminum (abbreviation: Alq₃), etc. To causethe luminous layer to emit blue light, a substance that emits lighthaving a peak of an emission spectrum of 420 nm to 500 nm may be used.Examples of the substance include, but are not limited to,9,10-bis(2-naphtyl)-tert-butylanthracene (abbreviation: t-BuDNA),9,9′-bianthryl, 9,10-diphenylanthracene (abbreviation: DPA),9,10-bis(2-naphtyl)-anthracene (abbreviation: DNA),bis(2-methyl-8-quinolinolato)-4-phenylphenolate-gallium (abbreviation:BGaq), bis(2-methyl-8-quinolinolato)-4-phenylphenolate-aluminum(abbreviation: BAlq), etc. Besides the substances that emit fluorescencedescribed above, a substance that emits phosphorescence may be used asthe light-emitting substance. Examples of the substance include, but arenot limited to,bis[2-(3,5-bis(trifluoromethyl)phenyl)pyridinate-N,C2′]iridium(III)picolinate(abbreviation: Ir(CF₃ppy)₂(pic)), bis[2-(4,6-difluorophenyl)pyridinate-N,C2′]iridium(III)acetylacetonate(abbreviation: FIr(acac)), bis[2-(4,6-difluorophenyl)pyridinate-N,C2′]iridium(III)picolinate (abbreviation:FIr(pic)), tris(2-phenylpyridinate-N,C2′)iridium (abbreviation:Ir(ppy)₃), etc.

The upper electrode 57 is a translucent electrode made of a translucentconductive material (translucent conductive oxide), such as ITO. Whilethe sixth embodiment uses ITO as an example of the translucentconductive material, the material is not limited thereto. A conductivematerial having a different composition, such as indium zinc oxide(IZO), may be used as the translucent conductive material. The upperelectrode 57 serves as the cathode (negative electrode) of the organiclight-emitting diode. The insulation layer 58 is a sealing layer thatseals the upper electrode 57 and is made of silicon oxide or siliconnitride, for example. The insulation layer 59 is a planarization layerthat suppresses unevenness caused by the bank and is made of siliconoxide or silicon nitride, for example. The substrate 50 is a translucentsubstrate that protects the entire image display panel and may be aglass substrate, for example. While the lower electrode 55 serves as theanode (positive electrode), and the upper electrode 57 serves as thecathode (negative electrode) in FIG. 57, for example, the embodiment isnot limited thereto. Alternatively, the lower electrode 55 may serve asthe cathode, and the upper electrode 57 may serve as the anode. In thiscase, the polarity of the drive transistor electrically coupled to thelower electrode 55 may be appropriately changed. The order of laminationof a carrier injection layer (the hole injection layer and the electroninjection layer), a carrier transport layer (the hole transport layerand the electron transport layer), and the luminous layer may beappropriately changed.

In a case where the electrode and the strain gauge in the displayapparatus are integrated like in the sixth embodiment and the thirdmodification, for example, the upper electrode 57 is integrated with theforce detector (e.g., one of the force detectors 91, 92, 93, and 94 andthe force detectors 91A, 92A, 93A, and 94A) in a similar manner to thedrive electrode COML according to the sixth embodiment and the thirdmodification.

The image display panel is a color display panel and includes the colorfilters 61. The color filters 61 are arranged between the respectivesub-pixels 49 and an image observer to transmit light in colorscorresponding to the colors of the respective sub-pixels 49 out of theluminous components of the light-emitting layer 56. The image displaypanel can emit light in colors corresponding to red, green, blue, andwhite. The color filter 61 is not necessarily arranged between thefourth sub-pixel 49W corresponding to white and the image observer. Theimage display panel can emit light in the colors corresponding to thefirst sub-pixel 49R, the second sub-pixel 49G, the third sub-pixel 49B,and the fourth sub-pixel 49W without transmitting the luminous componentof the light-emitting layer 56 through the color conversion layer, suchas the color filters 61. The fourth sub-pixel 49W in the image displaypanel, for example, may be provided with a transparent resin layerinstead of the color filter 61 for color adjustment. With thetransparent resin layer, the image display panel can suppress greatunevenness on the fourth sub-pixel 49W. The fourth sub-pixel 49W is notlimited to a white sub-pixel and may be a sub-pixel of another highluminance color, such as a yellow sub-pixel. In a case where a yellowsub-pixel is used as the fourth sub-pixel 49W, the image display panelmay include a white light-emitting layer 56 and a yellow color filter 61or the light-emitting layer 56 that emits yellow light.

Other advantageous effects that are provided by the aspects describedabove and that are obvious from the present specification orappropriately conceivable by those skilled in the art are naturallyprovided by the present invention.

What is claimed is:
 1. A detecting apparatus comprising: a touchdetection electrode provided along a touch detection surface; a straingauge integrated with the touch detection electrode.
 2. The detectingapparatus according to claim 1, further comprising a drive electrodethat is not in contact with the touch detection electrode and formscapacitance between the touch detection electrode and the driveelectrode.
 3. The detecting apparatus according to claim 2, furthercomprising: a touch detection electrode that is not provided with thestrain gauge; and a detector that detects force based on differencebetween an output in touch detection based on the capacitance of thetouch detection electrode integrated with the strain gauge and an outputin touch detection based on the capacitance of the touch detectionelectrode not provided with the strain gauge.
 4. The detecting apparatusaccording to claim 1, wherein the touch detection electrode is aself-capacitive electrode having capacitance that changes depending on atouch operation performed with the touch detection surface.
 5. Thedetecting apparatus according to claim 1, further comprising a detectorthat detects force based on electrical resistance in the touch detectionelectrode integrated with the strain gauge.
 6. A display apparatus inwhich a plurality of pixels are arranged in a matrix, the displayapparatus comprising: a drive electrode used to drive the pixels; and astrain gauge integrated with the drive electrode.
 7. The displayapparatus according to claim 6, wherein the drive electrode is not incontact with a touch detection electrode and forms an electric fieldbetween the touch detection electrode and the drive electrode accordingto a drive signal, and the display apparatus further comprises adetector that detects force based on an output timing of the drivesignal for forming the electric field and an output timing of a touchdetection signal from the touch detection electrode.